It’s all very context dependant… You need to evaluate in what aspects you have leverage or may be a threat with the specific person and suggest you may cause damage in that regard. You can do this by mentioning other situations with other people or anecdotes or whatever. For example, if you’re able to cause reputational damage to someone, you may mention about having a downfall with someone and hinting on how it was bad for them.

I’ll provode a concrete example from my life in my reply to the other person who asked in a min.

This is very nuanced and context specific. It should be done carefully, as all things should when dealing with psychos.