How do you use Buddhism to deal with toxic people?

Here's a video to remind us of predator types:

https://www.youtube.com/watch?v=djEKllJJukk&t=3s
Jordan Peterson - How Narcissistic Psychopaths Fool You

To me it would have to be Compassionate Wrath, and to use meditation to look unimpressed and bored like psychologists recommend with Grey Rock, or Ross Rosenberg's Observe, Don't Absorb practices (though these are hard to do). With wrath you have to make sure you don't turn into the monster you are having a conflict with. Heart-anger is more about engagement with the world, and requires A LOT OF PRACTICE to get good at.

https://www.atpweb.org/pdf/masters.pdf
Compassionate Wrath

http://psychreviews.org/testimonial-recovering-co-dependency-toxic-people-ross-rosenberg/
Observe, Don't Absorb

Recognize that the sensations you experience when dealing with that toxic person are not any different in nature from the sensations you experience when taking a poop. Laugh at your crappy insight, and notice that you're not bothered by the toxic person.

LOL!

That probably helps to a certain extent, but if they are your boss and you have a mortgage and kids, it's probably not so easy to do that. Or if you're married to a Cluster B personality disorder and going through divorce proceedings. Any leverage they have on you, and emotional investment from the past, will create some dukkha in the present. Though with strong mindfulness you'll weather it better than if you didn't meditate ever.

All joking aside, it's not so far off. I've been dealing with a number of very toxic customers lately in my job and it seems the best response is just to deal with them like anyone else. They're not special, they have no power over you. If anything they can be a really good teachers, if you remain mindful of your aversive reactions to their speech or actions. You can also learn a lot from watching how their behaviour influences their own view of the world. Toxic people don't seem particularly happy, for example.

One of our customers is stuck in the past, every time they come in they repeat a rant about things that happened to them 20 years ago, in detail even though it has nothing to do with our business. They then make demands, act rudely, make inappropriate sexual comments, the whole nine yards. While it's difficult for our staff to deal with them, it's been hard not to notice how miserable they are, and how that misery is tied directly to clinging to past events that are no longer remotely relevant to what is occuring now. It's also impossible to miss how that misery gets splashed onto everyone they encounter. While I try to be as compassionate as possible, it's been very educational.

Try to build happiness from jhanas before you deal. Dont say anything first but understand things first, then respond with best solution to everyone.

Orf for me : Try to take the stabs first, but let the emptiness inside you dissolve them, then see where is all those thoughts in your opponent’s head coming from, then see what they need best to serve them better.  

Im saying from this point as practisioner who experience little bit of jhana endless space and endless consciousness , emptiness, non perception nor nonperception (For me is sensing without putting identification)