I know that sociopathy (antisocial personality disorder) is knowing right from wrong but lacking inner moral compass that prevents the person from doing the wrong thing or feeling remorse for their actions. However, I want to know if there is a name for a disorder that causes the person to have moral direction and a sense of remorse, but is unable to tell right from wrong or lives by what they feel is right or wrong?
Basically I have a character who is downright crazy. Her problem is she thinks she's the good guy and she is always right, and believes that killing people who do wrong is justice. Example: her sister was born with FAS, so she blamed her mother for her sister's condition and tried to stab her in her sleep. She still thinks she was in the right when she did this.