When someone pulls a deadly weapon on you, the time for posturing and talking is over. Regardless of whether it’s an edged weapon, gun, or impact tool, at that point the adversary has displayed deadly intent. In terms of the Avoid, Escape, Confront, Resist paradigm, you should either be Escaping or Resisting not Confronting.
You might use some De-escalation words as you move away, but that’s merely a ploy to buy time not a serious attempt to defuse the situation.
“They say running is good for your health, in my neighborhood, it can save your life.” –Chicargo humor
The need for this mindset was very clear in the Calvin ‘Mad Dog’ Gonnigan incident https://wgntv.com/news/courts-man-killed-1-wounded-2-in-south-austin-after-plea-to-stop-shooting-gun-on-july-4/. It also applied to several other incidents that have been brought to my attention recently.
Practice changing direction quickly and be ready to do it at a moment’s notice. Break Contact as soon as you can.
Tactical Professor books (all PDF)
- Thinking Clearly about Self-defense and Personal Protection https://www.payloadz.com/go?id=3377208
- Indoor Range Practice Sessions http://indoorrangepracticesessions.com
- Concealed Carry Skills and Drills http://concealedcarryskillsanddrills.com
- Advanced Pistol Practice http://bit.ly/advancedpistolpractice
- Real Shootouts of the LAPD https://realshootoutsofthelapd.com/
- Serious Mistakes Gunowners Make http://seriousgunownermistakes.com
- Shooting Your Black Rifle http://shootingyourblackrifle.com
- Package deal of Thinking Clearly about Self-defense and Personal Protection, Serious Mistakes, Indoor Sessions, Concealed Carry, and Shooting Your Black Rifle (50% off) https://store.payloadz.com/details/2644448-ebooks-sports-shooting-drills-package.html
Purchase of any book includes Serious Mistakes Gunowners Make.
tacticalprofessor 
If you’re at a party, and someone starts shooting in the air, you’re at the wrong party. Time to leave, immediately.