Yusa blood demon art developed when she was cheated on by her 4 husband. She finally had enough humans to develop it. She can manipulate snakes and make them do her bidding. She can even make snakes via her own blood. Since she is the very second demon to be created she has a much higher resistance to Wisteria also due to her consuming and always being around it her entire human life. Her husband was caught cheating and so she ate the mistress and when her husband attacked her she regenerated and used her blood to make snakes come and kill him