Dwarf dude.

And he wasn't at all easy. I used every buff I had and he was still near-1 shotting me. The only way I beat him was by healing myself every turn and managing to get a few lucky shots in on him.

I was almost to the point of cheating a bit, but I wanted to do it without cheating. Either way, you can apparently go into the fight with your main character dead which makes your secondary character fight instead, and then resurrect your main character to 2v1 him. I still don't think it would have been easy.