Rui is Lower Rank Five, his Blood Demon Art is Threat Manipulation. He can create durable threads of silk from his flesh, capable of slicing nichirin swords, flesh, and nature. He lives on Mount Natagumo with the Spider Family; demons that he gave his abilities in exchange to play the role of a family, with Rui as the youngest kid. He expects everyone to play their role properly. He will dispose of family members that disobey him and just find someone new to play it. He is very authoritarian.