I'd like to try too, if possible. 
My idea is a guy with a reasonable amount of superstrength and superdurability whose main ability is nullification of any and all even remotely superhuman powers in a short range around him. Probably through the use of an alien eldritch artifact embedded into his body.
Name's "Pighead". Yes, a rehabilitated villain who spent quite a bit of time in Arkham or similar treatment center for crazy supervillains after three dozen bloody superhero murders - his unique shtick was not wearing a costume, coming really close and hitting them in the face with a meat cleaver. He really changed, has healed all of his mental deficiencies and wants to prove it.
Tell me if it's too grimdark, i am mostly familiar with the DC universe as with the place where most of villains are actually mad or posess other mental disorders instead of actually doing things out of sheer evilness or greed.