From https://www.bakadesuyo.com/2016/10/how-to-deal-with-psychopaths/

Here’s how to deal with a psychopath:

• Don’t. 1) Run. 2) Are you sure you can’t run?
• Accept that some people are just bad news: A tiger is not a good house pet. And you will not change that fact.
• Pay attention to actions, not words: No excuses. No BS. Use the “Rule of Threes.”
• Build your reputation and relationships: You need a good defense and good advice.
• Win-win agreements: Make it easier to go through you than to destroy you.

When in the middle of a deathmatch with a ruthless monster of a human being, being cynical is like having ESP. A jaded perspective can keep you one step ahead of them. But in the long term it can be toxic.

Don’t give up on all people just because you dealt with a really bad one.