77 Necro. Got all the way there, cleared the room by the snake pit and started whooping on him with the fight. He cheeses big time. Just keeps going into a trance where you can't attack him. Dots continue to work while he is tranced but you can't cast anything and pets and mercs can't attack. It seems like you would need the next few levels of spells and AA's to be able to have your dots take him out while he is tranced.
He summons if you get to much agg so make sure you have silent casting going.