Rage the Wolf was part of the Silent Planet army, he was one of the best in the warrior class but then quit for unknown reasons. Because he got an unknown rare disease after a battle and was put into suspended animation for a long time, when released he then was healed by Arthur who then become a good friend of his. When Arthur died, he promised to look after his family for him as a thank you for healing and befriending him, that is why he is now the protector of the Firefly family.