Captain Atomic is a superhero on Mighty Med. He was born Mario Steel, wounded in World War II. a radioactive bullet which should have penetrated his heart, but it was stopped by the lucky yo-yo given to him by his best gal. The bullet turned him radioactive, and the army fitted him with an experimental battery that keeps him alive, so he and his yo-yo are atomically powered. He was the "Tecton" of his time.
Now in the future, Captain Atomic becomes close friends with Kaz, Oliver and Skylar Storm