The king of Spirits. Jibaku Ou is powerful, but as he is very old he can no longer make much effort. In the anime he speaks a lot, can cast spells, and is the Spirit of Baku's father. In the anime, when Baku arrived at the 12th world, Jibaku Ou tried to force him to become a Great Soldier and take his father's place as ruler of World Zero, but he gives up after Baku shows his willpower in wanting to follow his dream without ceasing to be who he really is. In the manga, he is the Spirit of Utsurou, the true Great Child of Doidicus and the Great Soldier of World Zero, and unlike the anime he does not speak.