Kai had friends that work for the polices to protect this city. He really trust them. Until he founded out of what happened to his wife because of his friends. He accidentally picked his wife late from her work. So she took a walk to home. But, unfortunately she was not safe and got raped by a few of polices officer on her way home. He was devastated and out rage. He eventually killed every single of the polices to get his revenge. He would kill or do anything for her.