I do kinda wish he didn't have resistance to some piercing weapons(mainly the more limited ones, like the shadowbeam staff which already looses damage with each pierce it does or some flails which require playing risky to even get good damage off.) but that's just a personal thought.
It's really the only practical/easy way I can make him "uncheeseable". Sorry if it's an inconvenience
I might redo the AI for him in the future, all depends on the amount of time I have available.