How to be Eloquently Articulate in an emotional ambush and shit tests?

I want my mind to work fast enough so that it can manifest (demonstrate) itself through the smooth eloquence of my speech.

I want to develop the competency to verbally riposte (make a quick, clever reply to an insult or criticism.). To deflect and reverse the pressure when needed. To change the tables when you’re caught off-guard in a psychological ambush. And to give clever and intelligent responses to shit tests.