I thought I got left behind on this one. Apparently not. Ok I've got a couple concepts. Tell me which is more fitting for this story.
Cage- Cage is a walking, talking, nuclear meltdown. His body is a man shaped mass of yellow energy. This energy can be shot at enemies, detonated in a massive explosion, or simply allowed to leak all over the place. To prevent him from killing or poisoning everything in a three block radius, Cage is equipped with an armored suit. The suit is completely sealed, allowing Cage to move about densely populated areas without endangering lives. A valve on each hand allows him to shoot energy in a stream lined direction. Cage is not a superhero, he is a soldier. Whether or not his handlers are actually government agents, the military, or some other form of organization, I'll leave to the GM. Cage has been in service to his handlers since his powers manifested at the age of five. As long as Cage follows his orders, he is free to do as he pleases (as long as it's not to high profile). Cage has spent most of his life inside a suit, never being able to truly interact with the world around him. As a result he is very disconnected from the people he is charged with defending.
Bum (not his actual alias)- Powers: Increased senses, enhanced endurance, speed, and strength. Vinnie was raised in an orphanage for the first half of his childhood, before moving on to various shelters and allies after the orphanage got shut down. Vinnie had always been a little stronger then others his age, but he never thought much of it until he punched through his first brick wall. Despite his strength, Vinnie has no desire to use his power for ill gain. Instead he looks out for those who have no one else to look out for them. Where other heros turn a blind eye, Vinnie makes his home. He wears no costume and does not consider himself a "hero". Vinnie is just a guy, who does what he can, where he can.
(I know I said two, but here's a third) Dark- His hair is blown upward by an unseen wind. His eyes are twin pits of empty black space. He smiles when he kills, all while wearing a tailored suit. He is Dark. His name and origin are unknown. All that can be said for certain is that he is killing criminals, he is deadly, and he has no remorse.
Powers: Super senses, enhanced agility, speed, and endurance. Dark space- Dark can produce from his jacket any weapon which could have conceivably been concealed inside of it. He also never seems to run out of ammo.