Stan Lee's Superhero Kindergarten A former gym teacher turned superhero, Captain Fantastic, lost his superpowers in a battle with his nemesis, Dr. Superior. During this air battle, his superpower particles were transferred to six babies who were below. Five years later, the powerless Captain Fantastic, now known as Mr. Arnold, is called on to work 'undercover' as a kindergarten teacher to raise a new generation of super-powered kids.