I'm sure many of you remember "medium chill" approach being suggested on UB from time to time as a way to deal with difficult or narcissistic people. I just wanted to paste the link because it's coming in handy for me today dealing with a really invasive/negative colleague.
https://outofthefog.website/what-to-do-2/2015/12/3/medium-chill
This is the most ideal way to deal with narcissists. I have used it before I even knew it was a 'thing.' Just years of experience in dealing with family members who are narcs.