Totally agree. I don't want to out myself too much. During a couple of years separation, before his diagnosis (what he did during separation was the eye opener to see his narcissism, not realised until after reconciliation and I thought the separation was because there was millions of things wrong with me, as told to me by him and I believed) he could not be alone, he managed to coerce 3 women (who had been abused in previous relationships, he told me at the time these women had been treated so bad and 'just wanted a good man') in to 'relationships', every time it took him 2 to 3 weeks to realise they were flawed and he didn't want them any more so either immediately ghosted or devalued very quickly, only one of them lasted longer than a few weeks but that was because she had a game plan too (he was a meal ticket to her, brought her kids to sleep at her house after meeting him 3 times and, interestingly absolutely loved anything he said he liked, which was all made up crap which he put on a dating app to make himself look interesting) and lived far away so he could confine the relationship to one week day evening a week (there was no actual dates, he'd go to hers for telly/sex or she'd come to his with her kids).
When my rose coloured glasses were off I could see the processes he did with them that he did with me, but them in hyper speed time. The first 2 weeks of the relationships I can see he thought they were amazing and they were every thing to him, then they were nothing, an annoyance.
Interestingly no woman who had any sense of self wanted to go near him, he might get one date out of them but they would always say the same thing 'no connection' or they didn't feel anything.
He was OBSCESSED by dating, he was on every dating app, speed dating, he paid for swipes, I looked at his history once and the first thing he'd do when he woke up was go on the apps, all day long and the last thing he did before he went to sleep.
Talking about mirroring, when we were apart his personality and likes became everything I liked or wanted to do. He actually stalked me, although I didn't realise at the time. I went running, he started running, I went to the gym, so did he, I went for walks, so did he (and he'd hear/read places I'd want to go and he'd go there), he took women to pubs I frequented, I went dancing, so did he. You get the picture, the image he used on apps was mostly stolen from me with a sprinkling he stole from men he knew.