This movie caught my attention from the beginning and waited to see what would happen. The only problem here is that you do not have a real lesson to learn here, except “no relationship”.
The higher the score on me, the more likely it was to show some kind of syndrome or personality disorder and show something about it. As it is, the bad guy does not look like anything. Sometimes behave like a psychopath, but at other times they show some emotions that seem real (and they emerge when they are alone, so they do not imitate them, there are no viewers). It looks just semi-generic as Really Messed Up Person.