Basically, there are only two ways of coping with vindictive narcissists:
1. To Frighten Them
Narcissists live in a state of constant rage, repressed aggression, envy and hatred. They firmly believe that everyone is like them. As a result, they are paranoid, suspicious, scared and erratic. Frightening the narcissist is a powerful behaviour modification tool. If sufficiently deterred – the narcissist promptly disengages, gives up everything he was fighting for and sometimes make amends.
To act effectively, one has to identify the vulnerabilities and susceptibilities of the narcissist and strike repeated, escalating blows at them – until the narcissist lets go and vanishes.
If a narcissist is hiding a personal fact – one should use this to threaten him. One should drop cryptic hints that there are mysterious witnesses to the events and recently revealed evidence. The narcissist has a very vivid imagination. Let his imagination do the rest.