Your sister Barbar

You've always had a monster inside you. You lost your mother when you were very young. You also suffered a terrible trauma. You're a detective by day, but at night you become a serial killer who kills criminals who are guilty of crimes that escape the law or don't because of the corruption of the prison system. Barbara is your sister. She loves you very much. Of course, she's not your real sister, but she's the only one who really cares about you. There's a guy in your office named John who has a lot of doubts.