A powerful and really tough magical weapon that Jack created in Necropolis, so that he can play with Lavie and Blue. Even after Keel, Vamper and Toutan joined, they had hard time dealing with him. Eventually Lavie was the one that found it's weakness, which it's the source of magic, like most magical weapons. While opening it's big mouth on it's body to shoot laser beams, the round orb that is the source of magic, can be seen. So they made a strategy and a combination attack and where able to break the magical orb and thus Bonboun-kun.