XXI is an artificial test subject that was served to fuse the virus and humans together. Since she was physically weak and frail, She has helper Co Bots do most of her daily activities. She' may look like an expressionless, Quiet and careless little girl on the outside but in the inside she can get pretty vicious, dangerous and psychopatic. Her left eye is wrapped in bandages for unknown reasons. She has white hair and a pale complexion. She's small and petite. She has Co Bots of various sizes. 