Very interesting thread, but I just want to add a couple points.
1.) Everyone is going to encounter a narcissist, a psychopath, and various other oddities, but they won't be under every rock. They're a small minority. And some are much worse than others.
2.) Every cranky soul who's a bit selfish, or self centered, or manipulative, does not qualify as a clinical narcissist.
EVERY human has pride, and that causes all kinds of problems for all of us.
3.) These videos are talking about a clinical narcissist; it's a very extreme kind of thing. Let's be careful not to confuse it with the garden variety idiot relative who's selfish or always wants something.
4.) If you DO see this kind of personality type, and you're certain of it... just get away.
That's the only real solution.
(I know several clinical psychopaths who are born again believers. And although they understand sin and grace, and they'll be fully healed and restored in heaven, they are not fully healed down here. They are pretty strange characters. I have to fellowship with them in small doses.)
God Bless.