He's far from the only narcissist here
There are some good online tests to diagnose narcissism, psychopathy, sociopathy etc. I did some once and the results said I was pretty well the opposite of all three. Almost a shame since psychopaths seem to have a lot of fun.
About nationalities, although I know someone in PL who is certainly on the psychopathology scale and a slight narcissist too (she's actually a nice person albeit rather right wing and libertarian economically) I'd not say that Poland is a nation of narcissists, psychopaths at all; if anything most people in PL are empathetic.
russia though? Harder to say, however they do some things that suggest narcissism.
There's one nationality though that seem to me to be a nation of narcissists and psychopaths. Perhaps I've been personally unlucky in the ones I've interacted with however that would be statistically unlikely. There's one person I know from there who isn't on that scale and one poster here who also seems decent and not on that scale however they are both hyphen-whatsits with strong connections to other places.
The country? Can you guess what it is yet?
PS, the last sentence was a subtle clue.