What I did was use a combination of avenging angel and magic axe, i had beaten every enemy in the game up to this point i made sure i had skill like transmute and concentration , my intelligence stat was in the 20s. I used the viking berserker, polar bear, sea dog, and jutun (unsure if its right its the ice giant) also to keep my mana up in the end i used mana spring. It was a pretty tough fight maybe this will help maybe it won't but it is doable
