Lupis Rex/History

History
Rex's parents were marines who lived on Okami island while it was still a thriving Marine base. His father died in a battle against a group of rather murerous pirates near the beginning of the Great Pirate Era. His mother, a woman named Lupalina, raised him on her own, along with his older brother Lupis William. William left when Rex was 3 and he doesn't remember him much. His mother left herself when Rex was 10, leaving him to be raised by the Marines.

On Rex's 13th birthday, he discovered the Inu Inu no Mi and ate it. He lost control of the monster, which he later learned was called a Fenrir, and ended up killing every single Marine on the island. Rex eventually managed to calm down, and was horrified by what he saw. He isolated himself on the island, later renamed Okami island, and did his best to control the Fenrir. Unfortunately, he failed, and every night the Fenrir would return, reaking havoc wherever he was.

He tried to leave once, using the stars to navigate, but ended up slaughtering a small village on the first island he came across. That is how he gained his first bounty, and returned to Okami island.