Just walk away.
But I would be carefull with throwing around that label.
Technically we are all narcissists just on different levels.
Name a completely selfless deed?
It is impossible.. because everything comes back to yourself...
Some people just have different assosiations of what makes them guilty or lack thereof.
This is how you deal with them, ignore them. Narcissists are not decent people, don't let one rent space in your head.
I have know clue, maybe an arm bar.
They have to believe that doing so somehow benefits them.
You have to let it be known, mainly through actions, that you have a life, that you can pursue friendships, interests and other activities with absolutely no reference to the narcissist. You must command respect, first from yourself, and then from the narcissist. You must review the abuse and work out strategies to circumvent the cycle. If you find you cannot do that, then seriously, you need to find a way to get out of that relationship.
They have no respect for anything or anyone it is a social """"disorder""""" those who suffer from it are no better than anyone else. These people have minds that are damaged or cross wired