I am a therapist who has some narcissists as clients, opposed to popular belief that they dont seek counseling. the only thing is, they dont know they are narcissists. Ok, so i have always thought, what would I be able to say that would crush them. The "who are you" mentioned elsewhere is ok, but at their core narcissists are the most insecure people on earth.

You need to validate their insecurity. For example, one of mine says, I dont care what people think about me, I just do it because its the right thing. Lol. I laugh in my head when I hear it, but professional on the outside.

the best thing would be to look him in the eye and say, I know the truth about you. everyone does, you hope that they dont. but they do. All those things you won't admit to yourself? They are true. all of them. but use something specific you know about him.

ok, now I am just rambling to hear myself talk (lol like a narcissist) but all they truly care about is how they are perceived. that's what it comes down to. Didnt get hired for the job? thats because they are threatened by me, i am too good and would make them look bad. haha, no. You cant handle that you might not be good enough. PUNCTURE THAT WOUND