From one of. my abuse groups on Facebook:

"Ghosting a narcissist is a huge blow to their ego, one that causes a huge narcissistic injury and can potentially even lead to a narcissistic collapse (especially if they are struggling to line up replacement supply).

If you discard the narcissist and this catches them by surprise and in their view they are not ‘done' with you yet, expect them to give you the fight of your life to stay with them.

The narcissist needs to be the one doing the discarding, otherwise this inevitably causes them to accept their lack of control over you and lack of self-worth for being discarded. This forces them to see their ‘real-self' which is the vulnerable/ insecure person they spend their entire life running from.

You can expect the narcissist to try and reach out to you, and for all of the good things you ever saw in the narcissist to re-surface when they do. This is to confuse you and make you doubt your decision for leaving. Narcs are good at making you feel like you are letting go a part of yourself/ soul for leaving them. This is why it is important to cut ties and go no contact asap, otherwise they will try and reel you back in."