Once upon a time there was a little girl who loved cats. She was hit by a car and, if not for a young man locked away deep in the basement of a prison, she would have died.
Nagi, I need you helped her become Chrome Dokuro, and Chrome became a soldier for her beloved Mukuro-sama. In the year since Nagi became Chrome she's held her own with the best illusionist in the world for several minutes, she helped save the world a couple of times...including saving the future from someone trying to take over all the parallel worlds. She's spent more time dying in hospitals than anyone ought to have to cope with, she's been brain-washed, she's given her body over to someone else to use as his own, she's fought her way across enemy territory while missing most of her internal organs, and she's survived all of it.