Here is the subclass quest guide for the Kamael. This will allow the subclassing to any of the 2 other classes that you don't have, and once you finally reach level 75 in all 3 classes, you will be able to change class to Inspector/Judicator, which have many interesting skills.
Enjoy!
http://lineage2.stratics.com/content/library/quests/index.php?id=15237