Post apocalypse idea

My post apocalyptic idea is that the world was hit by a meteor. Radiation covered the earth and survivors sought shelter in domed cities. The radiation also gives people with unspecified requirements powers through mutation. The main character is one of these people. He lives in and protects one of the domed cities. The second character is a female assassin that hunts people with powers to bring them to a shadowy organization. The third is a "wild child", living in a cave far from the domed cities.