The Human Target
Adventurer
Another option came into my mind, though I doubt it will happen; A necromancer as a defender that defends from the back, summoning minions and other creatures to take the hits for the party; probably with a sort of spirit-companion like deal with his minions so he has to feed them his own lifeforce to sustain it. Would be breaking the mold, to be sure.
Yeah thats what my buddy was hoping for if they ever did one.