Final (Story) Boss - this spell ruined it lol

Gets to Misery, oh hey misery, lets get this epic battle started!

First attack, Spell Mutilate activates, Vicious pit worm auto attacks, Misery Dead.

Me: Wait… what? The hell just happen lol

So um… balance… maybe lets not let mutilate work on bosses? especially a final boss of the story lol. That was just silly.