I did it!!!!! It was embarrassing, I could have done it much earlier, but I was a total idiot and forgot the Virgin cross in my item. I didn't use it in this fight. hahaha How embarrassing. But hey, I almost managed to defeat him without the cross. I could withstand his strongest attack. With the cross it was child's play. I finally did it and the reward is amazing this ultimate attack is just great. Practically the same as the strongest vampire attack only instead of darkness light.