Green Lantern (John Stewart)

 John Stewart is a member of the Green Lantern Corps in the DC universe.

He is a marine soldier who was chosen by the corps to become a Green Lantern. As a kid, Stewart was a fan of comic books. His favorite superhero team was the Justice Guild. After an alien invasion, he and the world's greatest superheroes joined together to fight the aliens and became the Justice League. In one of his adventures, he learned the Justice Guild was from an alternate Earth.