Is it normal for good people to attract psychopaths?
When I was in high school, I met a young man who I'll call Duncan for anonymity's sake. Duncan and I played games and hung out in real life for years, but I first noticed some tendencies when playing an MMO with a guild. It started with some lies in order to defend himself, throwing not only myself but multiple others under the bus even though we had nothing to do with some incidents he was trying to handle. He even tried to peg me as some sort of dominatrix, something I'm not nor have any interest in becoming. We had a falling out, but like an idiot I forgave him after some time.
Then there's another issue, which I'll try to sum up quickly. He had tried some psychological conditioning by squeezing my stomach of all areas really painfully whenever I did something that even resembled an action he didn't like, mostly attacking his fragile ego with something rational. Thankfully I didn't fall for it, but he knew I would react to the pain, and if I were driving and mention anything he didn't agree with he'd threaten to do so subtly by placing his hand on my stomach as if to say "If you say what you're thinking, you're gonna kill us both", knowing the pain he'd cause would cause me to flail and get us both in an accident.
Recently I stopped talking to him, but knowing the damage he's caused makes me fear for the few friends I have who talk to him. His toxic behavior alone has lead to three close groups of online friends to disband, he's threatened me and multiple others including ex girlfriends with violence or even death, and he still has people who trust him over anyone else because of his multilayered behaviors that only get worse when you dig deeper.
Has anyone else met a person like this? Someone who acts like a good person to gain your trust even when they take off their mask and show how completely vile and cruel they are...