Alright students, get ready for a real rumble now! Fenrir is free to go help or stick around with Karnage. These guys are no joke, as they're skilled martial artists and have ice magic. But their durability is only a little bit better than an average humans (And that's mostly thanks to the ice armor their magic gives them) and while skilled in hand-to-hand, lack the raw strength to put much deadly force behind their blows. Death of a thousand cuts is their way. They work well as a team however, which I suggest you as well.
Also remember what your other task is: You have to hang up some charms to keep the low level demons from coming back and roosting. Though these Cannibal Masters don't seem too affected by it...