Kratei's Cube Entrance Manager:
Kratei's Cube allows 25 warriors who are level 70 and above to compete for 20 minutes to see who is the strongest. Warriors advance through the rooms of the Cube, encountering hordes of monsters as they go. Defeat as many monsters and other warriors as possible within the time limit; whoever defeats the most wins.
If you are killed, you will be teleported back to the Match Manager after 10 seconds. If the match hasn't ended, you may re-enter. Doing so will not decrease your experience score.
The 20-minute competitions start exactly on each hour and half-hour, and you can normally register up until 3 minutes before they begin. (If there was no competition in the previous time slot, you can only register between 20-27 minutes after the hour or 50-57 minutes after the hour.) Registration and admission are impossible in the 3 minutes immediately before a competition begins.