Recognize that they’re probably driven by some kind of narcissism and that responding to them in any way gives them narcissistic supply.

If you agree with them, you pad their ego. If you disagree with them, then they can feed themselves by “humbling” you.

The best way to engage is to disengage because you don’t actually fill any of your needs by engaging with them so just move on with your life, if possible. Don’t feed them and recognize your power in the situation is that you are in control of the attention supply, which is what they crave so turn that tap off and deny them what they want.

Being denied attention will hurt them more than anything because that’s how a narcissistic ego feeds and becomes validated.