8. They have dark interests or like things that make most people uncomfortable.
Narcissists, especially high on the spectrum, walk on the dark side and this shows in their obsession with things like the occult, mass murderers, the Holocaust, or weapons. They may listen to dark music such as death metal or watch slasher movies. Many people are interested in these things, but a malignant narcissist or psychopath, even if they put on a mask of being an upstanding moral citizen, usually have a secret hobby or interest in something dark or evil. They may not talk about it in public, but they have one.