Season 3 of Invincible hasn't even been released yet, but the show's creator, Robert Kirkman, believes the popular animated series could run for a long time to come. Based on Kirkman's graphic novel of the same name, Invincible follows Mark Grayson (Steven Yeun), the son of Omni-Man (J.K. Simmons), who, after discovering his own powers, sets out to become a superhero and save the world from a powerful threat.