Rui is a supervillain, but may have to become the hero of the story when the "hero" he creates is evil. He lives by his own set of rules, which causes many to consider him a weirdo. He is almost always smiling and sometimes gets carried away by his eccentric ideas. Despite the apparent riskiness of his ideas and the fact he's a villain , Rui does his best to take safety into consideration. He's very playful and teasing. He has many helper robots who help him out.