Captain Marvel was a Justice Lord in the early days. His soul reason for joining was in hopes of being a voice of reason among them. For the he earned Superman's hate. One day young Billy (Marvel's human form for those who don't know) was leaving for school when Superman swooped down and killed him in his weak child from. In this world the rest of the Marvel family was never formed. Marvel's ghost was still on this plane of existence due to his having unfinished business, to bring down the Justice Lords. Unfortunately only members of his family could see the ghost of Marvel. He bestowed the secrets apon his older sister Mary who joined the Rebels. With Marvel providing her with information and the powers of Captain Marvel she became Mary Marvel. A great aid to the Rebel cause.