Radiation would be the cause. That or stimulants or FEV. Of course, we couldn't be Superman or Dr. Manhattan, we'd be fairly weak in comparison to those, we'd be semi-super, you know, advanced jumping and running, maybe laser vision, semi-invisibility, power to turn into mist, Telekinesis, mind-reading, stuff like that. We'd also use guns, because not all of us would have offensive powers or unlimited energy. Now, I would be the one to make it, but it may be a while, probably a week or two, until I could create the thread.