I stand toe to toe with slasher on my sampire while archers and mystic mages hit him. The only time I have any trouble is when he freezes me. I can get one, sometimes two heal pots off and then will have to run the second I can move. I run without healing skill btw... If you had two dexers xhealing I have no doubt you could do Slasher. I still haven't tried Stygian Dragon yet. I'll update whenever I do to let you know how it goes.