Blacksmith Vincenz:
First off, you can't use old Soul Crystals anymore. To bestow the new special abilities, you need the new Soul Crystals. You can get them by defeating bosses or raid monsters.
When you get the Soul Crystals, then you can combine them to make an upgraded Soul Crystal. For combination, you need two Soul Crystals of the same type and the same stage. However, there is a chance of failure. If the combination fails, one of the two Soul Crystals will disappear.
In any case, by doing this, you can get your desired Soul Crystal class and then give the ability to a weapon.
"Tell me about practice."