Malevolent Sociopaths
Also know as Sadistic-Paranoid Sociopaths, these people are aggressive and often have delusions about friends. S/he believes that some friends are out to harm him/her, and tries to punish them for it. They may or may not be innocent. They enjoy punishing the people, and enjoy watching them suffer for what he/she thinks they did. Particularly difficult to help out as they generally don't trust psychologists and think they are trying to trick them.