Yeah, I watched my friends play against him and with him. His passive, Death Sentence, and Flay make him a bit OP. After a while, my friends say you can just make him all ad and he will wreck because of Damnation, his passive. From what the tags say, he is mostly supposed to be support and tanky, but he seems more like a champion that can be anything.
Maybe you can make it so he loses some of his souls if he dies, that way his passive doesn't make him so OP. His other skills, not quite sure how you can fix that quite yet. If I think of an idea, I will edit this.