I'm thinking tank/powerhouse kind of powers. Still working it out in my mind, but basically a superhuman physique with a mystical origin relating to weird ancient rituals he learned from album sleeves. Or something like that. And an ability to fight learned from moshing and brawling in the street. 

And I didn't want to play a bad guy. I just figured that in a world with "The Masked Asshole", that this would be a totally appropriate character concept. 

Besides, there have been tons of good guys with dark/demonic styles/powers/origins. He might not necessarily get along too well with a super-hippie, but he's not evil. If anything he'd be more of dethklok meets a young batman type. A dark knight. Scary enough to scare the bad guys type of hero, while still being someone you might see listening to king daimond with jay and silent bob.

I  mean I could even put in a spiderman-esque backstory to give him some extra "good" motivation if he's sounding too dark for you.