I have encountered only one psychopathic personality, although I have read much about them.
Psychopathic personalities delight in hurting people. That's what gets them off. Not necessarily physical torture but mental torture. Please don't confuse that with people who indulge in BDSM (not my thing, but I know people who enjoy it) because everything they do is
consensual.
My encounter with that psychopathic personality led me to understand these things about his behaviour. It's not valid to generalize from one example, but from what I've read it seems to fit the general profile.
- He enjoyed "warning" people about what he would do. In reality, he enjoyed the fear they expressed at what they thought he might do.
- He also enjoyed his "warnings" because it let him feel superior. He gave them a handicap. Even forewarned, they were no match for his mighty intellect. In reality he'd rigged the game in advance so that the warning did them no good. But even a psychopath has to bolster his ego.
- He enjoyed rubbing in what he'd done afterwards. It increased the suffering.
What you saw was typical (if my experience and reading is anything to go by) psychopathic behaviour. The irony of attacking others for what he does himself adding insult to injury. Which is what psychopaths get off on.