Crona is a 16-year-old girl who was used in experiments by her mother, she doesn't trust an her anyone, her blood is black and she has life and her own name is called ragnarok, ragnarok physically abuses crona for what she became antisocial and repressed, she will not hesitate to kill if ordered to, she is crazy and usually when she is ordered to kill she puts on a terrifying smile, ragnarok transforms into a sword with which Crona fights, She is not good at talking to women, or people