Ŕosa works for Project Persona, an organization that studies human concience. Her name there is Thirteen. She has a giant hammer, and can swing it effortlessly, though she is only 11 years old. She can also charge herself with mana, and when she does, light-blue energy courses through her and her hammer, allowing for extra-destructive swings. She is impatient, and even though she's young, and exploited by a government organization, she hits hard.