Nathan Fillion, Green Lantern Nathan Fillion, Green Lantern

He may solve crimes by day as Richard Castle on ABC's Castle, but it's a well-known fact that sci-fi icon Nathan Fillion's true passion is the world of comic books and superheroes. Fillion voices Green Lantern in Warner Home Video's Justice League: Doom (available now on DVD, Blu-ray, for download and on demand), and sat down to discuss the notable memorabilia he's collected from each of his performances and the type of genres that entertain him. Check out exclusive excerpts from the interview below!