I have met two manual narcissists in my life: one, a close friend, the other one, my step mum.
What I regret the most is that it took me years to realise what the dynamics of the relationship was like. They belittled me and humilated me, they always made me feel as if they were superior and their lives were more worth living than mine, they portrayed themselves as wonderful, and I believed them for a while, but the reality is that they only care about themselves.
They just want to be the centre of attention and control the people around them in subtle and not so subtle ways. They badmouth you behind your back, so they destroy other friendships or relationships you might have.
They are always the victim and they make it look as if they have a higher moral ground over you. They make you feel as if you owe them something all the time. They are draining, and they don't leave anything positive in your life, other than heartbreak.
My advice is to cut all ties, learn from the experience and if you ever come across anybody who shows narcissistic traits, run a mile.
You don't need to be trained in psychology to spot a narcissist. It's a personality disorder that is not treated like other disorders like bipolar or borderline personality disorder, as in most cases these people are fully functional members of society and they usually have professional success, so it is very hard to see them as mentally ill.
They are not mentally ill either, they are just toxic and manipulative people whose thirst for power and control destroys all relationships around you, together with your sense of self and self worth.