He wrote the screenplay for Ultimate Avengers, Ultimate Avengers II, The Invincible Iron Man, Doctor Strange: The Sorcerer Supreme Planet Hulk, and Thor: Tales of Asgard. He wrote the screen story on Next Avengers: Heroes of Tomorrow. He was a writer on The Incredible Hulk and Wolverine and the X-Men. story editor on The Incredible Hulk. He served as head writer, story writer, executive story editor, story by, and producer on X-Men: Evolution.