Angelo's description exactly encapsulated the person I was with.
There has been a lot of discussion around the DSM committee's decision to drop NPD, including an immense amount of superficial journalism, which is nearly all hopelessly off-track. None of the journalists delve any further than noting the "grandiosity" of a narcissist and don't have any experience with narcissistic manipulation. The main problem, as those who have been in relationships with narcissts will know, isn't "grandiosity" -- that aspect of the disorder is at worst tiresome. The really destructive part of clinical narcissism is the "gaslighting" that makes untangling emotionally brutalizing conflict impossible.
The five-year experience I had with a narcissist can serve to illustrate this point. This woman is admirable in her community involvement, she is intellectually curious -- and of course she is self-confident and outspoken in ways that at first seem very healthy. In sum, to everyone she isn't intimate with, she is a complete breath of fresh air. But later, she harped condescendingly and vaguely that her "trust" in me was depleting, and what was left was a hard, unrelentingly stigmatizing, angry person.
For people trying to make sense of this sort of relationship arc, I believe it's worth clarifying something: It often comes across in our remarks as though narcissists were obvious monsters off the bat, so we should never have invested in those relationships. On the contrary, the most disturbing thing is just how much of a good thing the narcissist is intent on throwing away. The narcissist often expresses stalwart faith that the relationship is what they want at the beginning. They may make genuine efforts at the outset to be a considerate partner. Over time, though, strong bonds they may actually want turn out to be poison to their overriding compulsion to keep themselves remote from all honest, insightful critique.
When a relationship with a narcissist gets more committed and more complicated, the dynamics become thoroughly bizarre and untethered from the part of the person the partner originally knew. This is more than a case of being with someone with "a wandering eye." There is a disruptive pride and unremitting resentment at work, but kept out of direct view whenever possible.
At the outset, the narcissist hides from critiques in ways that come across as just aggravating character "blindspots," while the dialogue in the relationship may seem otherwise constructive. Later on, the contributions the partner makes to bettering a relationship only seem to prompt the narcissist to "move the goalposts," and swamp progress with their anger. Gradually, the pattern becomes evident, that the insecurity the narcissist is experiencing isn't a particular complaint, but is a defense to prevent access to their thinking -- and to ward off any further open exchange in a relationship.
At that point, while they can "compromise" on some issues, they paint in more and more stigmatizing terms the burdens that the partner represents to them. They grossly devalue even the most sacrosanct pursuits and connections they share with the partner. Someone who in other contexts is a scintillating conversationalist has no "patience" for dialogue that suggests shared responsibility for conflict, and they cannot enter these difficult relationship conversations on an up note. They "remember" only the most problematic parts of earlier conversations, and sounding like "bad historians," may recycle "settled" complaints at random from other long-ago conversations to steer the topic away from them. They characterize their partners as overcome by emotionality and weakness. At the mention (even in writing) of contributions the narcissist has been making to conflict, they often angrily derail the discussion, sometimes with wholly disproportionate and even laughably distorted outbursts. At no time will they evince any insecurity, yet they make it nearly impossible to focus the discussion any deeper on their patterns of behavior. The point is to entangle the partner in argument rather than arrive at clearer understanding.
At a certain point, the narcissist no longer has any effective means of deflecting critical insights into their character. Making amends is impossible for them, so the less they are compelled to look back, the better. The narcissist often calculates that it is safest to sacrifice the entire connection -- leaving the relationship either formally, emotionally, or covertly -- and becomes firmly committed to propagating the view that the partner made the situation impossible.
Good people can take a long time to write off a loved one or reach this diagnosis. After it is apparent that the narcissist isn't who they appeared to be, a victim can start divorcing themselves emotionally and regain their agency. But the disrupted goals and time sucked away are compounded by an unsettling portrait of emotional betrayal. That is its own sense of agony, just like in the most painful divorces.
It's important not to make a diagnosis that a partner is a narcissist without taking a therapist's views on board -- both for the dignity of the person under the microscope, and to make sure, if you are the one hooked, you are getting a clearer perspective on the dynamics. The painful bewilderment that comes with these relationships is almost always unavoidable because of how truly senseless their anger becomes: Narcissists are capable of appearing solid and intelligent, but then inexplicably begin evaporating into an incoherent miasma of distortions and dishonesty. As they begin revealing their other side, they deflect observations suggesting that they were, once-upon-a-time, capable of being a more considerate person.
If in your case too, the experiences do line up, then consider if it is appropriate to step up and gently forewarn the next partner. It may or may not be. Above all, don't make a scene, either by speaking from the gut to the next partner, or by too freely offering what will just come across as "psychobabble." As you won't be received by the next partner as delivering an epiphany, just a heartfelt heads-up, try to figure out exactly how an NPD pattern fits AND doesn't. Paint a full portrait that would be familiar to the next partner -- including what is initially enchanting about the narcissist. Further, skepticism on the next partner's part is the normal response, and so word is probably going to filter back to your ex, who will almost certainly then paint you as the kind of person who was primed to impute just such shamefully inappropriate "distortions" of her personality.
In my case, I did decide to warn her next partner, and after a year's hiatus, he got back in touch to say the picture was clear. From that point on, we pieced together something else about her: While in relationships with each of us, she'd been pointedly lying to both of us to cover for on-and-off affairs.
Never underestimate the scope of a narcissist's uses of deception. Indeed, the only guess I can hazard is that for her, living out those kinds of affairs was a predatory behavior. Betrayals helped her more comfortably rationalize the protective beliefs she holds. After all, having confirmed in her own mind that we were simple dupes, she could pardon herself from any thorough self-examination of the truth about herself -- that she has fashioned her entire life around misrepresentations and dishonesty.