diff --git a/L2J_Mobius_1.0_Ertheia/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_1.0_Ertheia/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 998d18643b..29a3deea8e 100644
--- a/L2J_Mobius_1.0_Ertheia/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_1.0_Ertheia/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1070,6 +1074,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_1.0_Ertheia/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_1.0_Ertheia/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index f0e51705a0..2353ceddf0 100644
--- a/L2J_Mobius_1.0_Ertheia/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_1.0_Ertheia/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -981,6 +981,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -992,6 +996,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_2.5_Underground/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_2.5_Underground/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 98c4f9f99c..ae62ac9508 100644
--- a/L2J_Mobius_2.5_Underground/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_2.5_Underground/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1070,6 +1074,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_2.5_Underground/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_2.5_Underground/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index f0e51705a0..2353ceddf0 100644
--- a/L2J_Mobius_2.5_Underground/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_2.5_Underground/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -981,6 +981,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -992,6 +996,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_3.0_Helios/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_3.0_Helios/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 98c4f9f99c..ae62ac9508 100644
--- a/L2J_Mobius_3.0_Helios/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_3.0_Helios/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1070,6 +1074,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_3.0_Helios/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_3.0_Helios/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index bce4f6845e..a8ada435be 100644
--- a/L2J_Mobius_3.0_Helios/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_3.0_Helios/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -982,6 +982,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -993,6 +997,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_4.0_GrandCrusade/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_4.0_GrandCrusade/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 98c4f9f99c..ae62ac9508 100644
--- a/L2J_Mobius_4.0_GrandCrusade/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_4.0_GrandCrusade/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1070,6 +1074,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_4.0_GrandCrusade/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_4.0_GrandCrusade/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index bce4f6845e..a8ada435be 100644
--- a/L2J_Mobius_4.0_GrandCrusade/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_4.0_GrandCrusade/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -982,6 +982,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -993,6 +997,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_5.0_Salvation/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_5.0_Salvation/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 98c4f9f99c..ae62ac9508 100644
--- a/L2J_Mobius_5.0_Salvation/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_5.0_Salvation/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1070,6 +1074,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_5.0_Salvation/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_5.0_Salvation/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index bce4f6845e..a8ada435be 100644
--- a/L2J_Mobius_5.0_Salvation/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_5.0_Salvation/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -982,6 +982,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -993,6 +997,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_5.5_EtinasFate/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_5.5_EtinasFate/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 98c4f9f99c..ae62ac9508 100644
--- a/L2J_Mobius_5.5_EtinasFate/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_5.5_EtinasFate/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1070,6 +1074,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_5.5_EtinasFate/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_5.5_EtinasFate/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index bce4f6845e..a8ada435be 100644
--- a/L2J_Mobius_5.5_EtinasFate/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_5.5_EtinasFate/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -982,6 +982,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -993,6 +997,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_6.0_Fafurion/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_6.0_Fafurion/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 98c4f9f99c..ae62ac9508 100644
--- a/L2J_Mobius_6.0_Fafurion/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_6.0_Fafurion/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1070,6 +1074,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_6.0_Fafurion/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_6.0_Fafurion/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index bce4f6845e..a8ada435be 100644
--- a/L2J_Mobius_6.0_Fafurion/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_6.0_Fafurion/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -982,6 +982,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -993,6 +997,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_7.0_PreludeOfWar/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_7.0_PreludeOfWar/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 98c4f9f99c..ae62ac9508 100644
--- a/L2J_Mobius_7.0_PreludeOfWar/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_7.0_PreludeOfWar/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1070,6 +1074,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_7.0_PreludeOfWar/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_7.0_PreludeOfWar/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index bce4f6845e..a8ada435be 100644
--- a/L2J_Mobius_7.0_PreludeOfWar/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_7.0_PreludeOfWar/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -982,6 +982,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -993,6 +997,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_8.0_Homunculus/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_8.0_Homunculus/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 3947541ddb..b3f7db3fa1 100644
--- a/L2J_Mobius_8.0_Homunculus/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_8.0_Homunculus/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1071,6 +1075,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_8.0_Homunculus/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_8.0_Homunculus/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index bce4f6845e..a8ada435be 100644
--- a/L2J_Mobius_8.0_Homunculus/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_8.0_Homunculus/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -982,6 +982,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -993,6 +997,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_9.0_ReturnOfTheQueenAnt/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_9.0_ReturnOfTheQueenAnt/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 3947541ddb..b3f7db3fa1 100644
--- a/L2J_Mobius_9.0_ReturnOfTheQueenAnt/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_9.0_ReturnOfTheQueenAnt/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1071,6 +1075,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_9.0_ReturnOfTheQueenAnt/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_9.0_ReturnOfTheQueenAnt/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index bce4f6845e..a8ada435be 100644
--- a/L2J_Mobius_9.0_ReturnOfTheQueenAnt/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_9.0_ReturnOfTheQueenAnt/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -982,6 +982,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -993,6 +997,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_CT_2.4_Epilogue/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_CT_2.4_Epilogue/java/org/l2jmobius/gameserver/model/actor/Npc.java
index a03ca2e2a7..922513c085 100644
--- a/L2J_Mobius_CT_2.4_Epilogue/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_CT_2.4_Epilogue/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -21,6 +21,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
@@ -114,6 +115,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1272,6 +1275,7 @@ public class Npc extends Creature
 		_killingBlowWeaponId = 0;
 		_isRandomAnimationEnabled = getTemplate().isRandomAnimationEnabled();
 		_isRandomWalkingEnabled = !WalkingManager.getInstance().isTargeted(this) && getTemplate().isRandomWalkEnabled();
+		
 		if (isTeleporting())
 		{
 			EventDispatcher.getInstance().notifyEventAsync(new OnNpcTeleport(this), this);
@@ -1285,6 +1289,16 @@ public class Npc extends Creature
 		{
 			WalkingManager.getInstance().onSpawn(this);
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_CT_2.4_Epilogue/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_CT_2.4_Epilogue/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index 5176affd4c..9b2f2cefcc 100644
--- a/L2J_Mobius_CT_2.4_Epilogue/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_CT_2.4_Epilogue/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -843,6 +843,10 @@ public abstract class AbstractScript extends ManagedScript
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -854,6 +858,10 @@ public abstract class AbstractScript extends ManagedScript
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_CT_2.6_HighFive/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_CT_2.6_HighFive/java/org/l2jmobius/gameserver/model/actor/Npc.java
index a03ca2e2a7..922513c085 100644
--- a/L2J_Mobius_CT_2.6_HighFive/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_CT_2.6_HighFive/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -21,6 +21,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
@@ -114,6 +115,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1272,6 +1275,7 @@ public class Npc extends Creature
 		_killingBlowWeaponId = 0;
 		_isRandomAnimationEnabled = getTemplate().isRandomAnimationEnabled();
 		_isRandomWalkingEnabled = !WalkingManager.getInstance().isTargeted(this) && getTemplate().isRandomWalkEnabled();
+		
 		if (isTeleporting())
 		{
 			EventDispatcher.getInstance().notifyEventAsync(new OnNpcTeleport(this), this);
@@ -1285,6 +1289,16 @@ public class Npc extends Creature
 		{
 			WalkingManager.getInstance().onSpawn(this);
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_CT_2.6_HighFive/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_CT_2.6_HighFive/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index 5176affd4c..9b2f2cefcc 100644
--- a/L2J_Mobius_CT_2.6_HighFive/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_CT_2.6_HighFive/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -843,6 +843,10 @@ public abstract class AbstractScript extends ManagedScript
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -854,6 +858,10 @@ public abstract class AbstractScript extends ManagedScript
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_Classic_2.0_Saviors/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_Classic_2.0_Saviors/java/org/l2jmobius/gameserver/model/actor/Npc.java
index a3c8d420b2..5ed095baa4 100644
--- a/L2J_Mobius_Classic_2.0_Saviors/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_Classic_2.0_Saviors/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1070,6 +1074,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_Classic_2.0_Saviors/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_Classic_2.0_Saviors/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index 8a2109f5b2..bd7368f305 100644
--- a/L2J_Mobius_Classic_2.0_Saviors/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_Classic_2.0_Saviors/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -956,6 +956,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -967,6 +971,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_Classic_2.1_Zaken/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_Classic_2.1_Zaken/java/org/l2jmobius/gameserver/model/actor/Npc.java
index a3c8d420b2..5ed095baa4 100644
--- a/L2J_Mobius_Classic_2.1_Zaken/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_Classic_2.1_Zaken/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1070,6 +1074,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_Classic_2.1_Zaken/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_Classic_2.1_Zaken/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index 8a2109f5b2..bd7368f305 100644
--- a/L2J_Mobius_Classic_2.1_Zaken/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_Classic_2.1_Zaken/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -956,6 +956,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -967,6 +971,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_Classic_2.2_Antharas/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_Classic_2.2_Antharas/java/org/l2jmobius/gameserver/model/actor/Npc.java
index a3c8d420b2..5ed095baa4 100644
--- a/L2J_Mobius_Classic_2.2_Antharas/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_Classic_2.2_Antharas/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -116,6 +118,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1070,6 +1074,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_Classic_2.2_Antharas/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_Classic_2.2_Antharas/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index 8a2109f5b2..bd7368f305 100644
--- a/L2J_Mobius_Classic_2.2_Antharas/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_Classic_2.2_Antharas/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -956,6 +956,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -967,6 +971,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_Classic_2.3_SevenSigns/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_Classic_2.3_SevenSigns/java/org/l2jmobius/gameserver/model/actor/Npc.java
index b6ae6c8945..050f15b78d 100644
--- a/L2J_Mobius_Classic_2.3_SevenSigns/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_Classic_2.3_SevenSigns/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -117,6 +119,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1082,6 +1086,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_Classic_2.3_SevenSigns/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_Classic_2.3_SevenSigns/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index 8a2109f5b2..bd7368f305 100644
--- a/L2J_Mobius_Classic_2.3_SevenSigns/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_Classic_2.3_SevenSigns/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -956,6 +956,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -967,6 +971,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_Classic_2.4_SecretOfEmpire/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_Classic_2.4_SecretOfEmpire/java/org/l2jmobius/gameserver/model/actor/Npc.java
index b6ae6c8945..050f15b78d 100644
--- a/L2J_Mobius_Classic_2.4_SecretOfEmpire/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_Classic_2.4_SecretOfEmpire/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -117,6 +119,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1082,6 +1086,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_Classic_2.4_SecretOfEmpire/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_Classic_2.4_SecretOfEmpire/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index 8a2109f5b2..bd7368f305 100644
--- a/L2J_Mobius_Classic_2.4_SecretOfEmpire/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_Classic_2.4_SecretOfEmpire/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -956,6 +956,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -967,6 +971,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_Classic_3.0_TheKamael/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_Classic_3.0_TheKamael/java/org/l2jmobius/gameserver/model/actor/Npc.java
index b6ae6c8945..050f15b78d 100644
--- a/L2J_Mobius_Classic_3.0_TheKamael/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_Classic_3.0_TheKamael/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -117,6 +119,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1082,6 +1086,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_Classic_3.0_TheKamael/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_Classic_3.0_TheKamael/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index 8a2109f5b2..bd7368f305 100644
--- a/L2J_Mobius_Classic_3.0_TheKamael/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_Classic_3.0_TheKamael/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -956,6 +956,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -967,6 +971,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_Classic_Interlude/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_Classic_Interlude/java/org/l2jmobius/gameserver/model/actor/Npc.java
index cf1126298f..044002951d 100644
--- a/L2J_Mobius_Classic_Interlude/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_Classic_Interlude/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -114,6 +116,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1054,6 +1058,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_Classic_Interlude/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_Classic_Interlude/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index 8a2109f5b2..bd7368f305 100644
--- a/L2J_Mobius_Classic_Interlude/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_Classic_Interlude/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -956,6 +956,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -967,6 +971,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_Essence_4.0_DwellingOfSpirits/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_Essence_4.0_DwellingOfSpirits/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 194aad174c..6fbde3d9db 100644
--- a/L2J_Mobius_Essence_4.0_DwellingOfSpirits/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_Essence_4.0_DwellingOfSpirits/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -117,6 +119,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1083,6 +1087,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_Essence_4.0_DwellingOfSpirits/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_Essence_4.0_DwellingOfSpirits/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index 197980b2ac..58a82f6f76 100644
--- a/L2J_Mobius_Essence_4.0_DwellingOfSpirits/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_Essence_4.0_DwellingOfSpirits/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -957,6 +957,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -968,6 +972,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_Essence_5.0_Sylph/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_Essence_5.0_Sylph/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 194aad174c..6fbde3d9db 100644
--- a/L2J_Mobius_Essence_5.0_Sylph/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_Essence_5.0_Sylph/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -117,6 +119,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1083,6 +1087,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_Essence_5.0_Sylph/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_Essence_5.0_Sylph/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index 197980b2ac..58a82f6f76 100644
--- a/L2J_Mobius_Essence_5.0_Sylph/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_Essence_5.0_Sylph/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -957,6 +957,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -968,6 +972,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
diff --git a/L2J_Mobius_Essence_5.5_FrostLord/java/org/l2jmobius/gameserver/model/actor/Npc.java b/L2J_Mobius_Essence_5.5_FrostLord/java/org/l2jmobius/gameserver/model/actor/Npc.java
index 194aad174c..6fbde3d9db 100644
--- a/L2J_Mobius_Essence_5.5_FrostLord/java/org/l2jmobius/gameserver/model/actor/Npc.java
+++ b/L2J_Mobius_Essence_5.5_FrostLord/java/org/l2jmobius/gameserver/model/actor/Npc.java
@@ -18,6 +18,8 @@ package org.l2jmobius.gameserver.model.actor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 
 import org.l2jmobius.Config;
@@ -117,6 +119,8 @@ public class Npc extends Creature
 	public static final int INTERACTION_DISTANCE = 250;
 	/** Maximum distance where the drop may appear given this NPC position. */
 	public static final int RANDOM_ITEM_DROP_LIMIT = 70;
+	/** Ids of NPCs that see creatures through the OnCreatureSee event. */
+	private static final Set<Integer> CREATURE_SEE_IDS = ConcurrentHashMap.newKeySet();
 	/** The Spawn object that manage this NpcInstance */
 	private Spawn _spawn;
 	/** The flag to specify if this NpcInstance is busy */
@@ -1083,6 +1087,16 @@ public class Npc extends Creature
 		{
 			setClanId(getCastle().getOwnerId());
 		}
+		
+		if (CREATURE_SEE_IDS.contains(getId()))
+		{
+			initSeenCreatures();
+		}
+	}
+	
+	public static void addCreatureSeeId(int id)
+	{
+		CREATURE_SEE_IDS.add(id);
 	}
 	
 	/**
diff --git a/L2J_Mobius_Essence_5.5_FrostLord/java/org/l2jmobius/gameserver/model/events/AbstractScript.java b/L2J_Mobius_Essence_5.5_FrostLord/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
index 197980b2ac..58a82f6f76 100644
--- a/L2J_Mobius_Essence_5.5_FrostLord/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
+++ b/L2J_Mobius_Essence_5.5_FrostLord/java/org/l2jmobius/gameserver/model/events/AbstractScript.java
@@ -957,6 +957,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, int... npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}
 	
@@ -968,6 +972,10 @@ public abstract class AbstractScript extends ManagedScript implements IEventTime
 	 */
 	protected final List<AbstractEventListener> setCreatureSeeId(Consumer<OnCreatureSee> callback, Collection<Integer> npcIds)
 	{
+		for (int id : npcIds)
+		{
+			Npc.addCreatureSeeId(id);
+		}
 		return registerConsumer(callback, EventType.ON_CREATURE_SEE, ListenerRegisterType.NPC, npcIds);
 	}