I hesitate to share this here... but uh, whatever.
"You’re a beautiful aware person. Alas, the world is not full of such people. Difficult people — who bluster, bully, threaten, intimidate to get their way — outnumber you. So how should you deal with them?"
"[...] Here’s the secret of dealing with difficult people. Don’t. Help them not to be [difficult] instead. Don’t deal with them doesn’t mean: ignore them. [Don't deal with them] means: don’t take their deal, [don't] accept cards from their deck. [Difficult people] think they must treat every tiny interaction as a negotiation, a battle, a war. Dealing, double dealing, wheeling and dealing. Don’t play their game. Help them learn, feel, know why it is a bad [game]."
"(How to Deal With) Difficult People", by Umair Haque on Medium -- https://medium.com/on-arete/how-to-deal-with-difficult-people-7f7dd90be7b3
// I would like to note that the article deals with Difficult people. Not suicidal-homicidal people. (Which are somewhat similar to "difficult people", but are on a whole order of magnitude higher difference in intensity and psychosis, I think.)