The Illusionist is a hybrid Cleric and Thief, which is as strange a combination as it seems. Low-level Cleric Spells are useful to have, but it's easy to get some steal and disarm skill in a more powerful hybrid. The Illusionist lacks decent gear selections, and you probably don't want them at the head of the party in dungeons to disarm traps. The only real upside is that a Fuzzy Illusionist has some fantastic Stats.