Oh btw..............2 things.
Sorry, but I'm playing on the pc and I think this is a thread for console ?! Hope that is ok ?
2nd, I don't think that griffin de-buffs ALL the time. What I mean is, that he will de-buff you for sure, but if you immediately re-buff yourself he won't zap you again for a while. I'm thinking that he can only cast the de-buff spell occationally rather than constantly. I've beaten him with 4 or 5 classes now without too much bother. Like I said, just re-buff yourself and kick it's behind. Apart from the de-buff spell, he is a bit of a wimp. So much so that I can't even remember using a single health pot ! Go for it.
Steve.