Word for the ability to deliver clever replies? [duplicate]

What do we call the person who comes back with clever replies when someone insults them?

Also what is this ability (personality trait) to cleverly thrash rivals on-the-spot called?

Example:

Person A: "I can't bear fools."

Person B: "Apparently, your mother could..."

What should I call Person B in this?

What is the personality trait he possesses that made him comeback so cleverly against the insult?

witty (adjective)

These words describe the ability to make quick, sharp, clever comebacks.

Winston Churchill was famous for his quick and biting wit:

Member of Parliament, Nancy Astor, speaking to Winston Churchill:

If I were your wife I would poison your coffee..

Churchill:

If you were my wife, I would drink it.

Member of Parliament, Bessie Braddock, speaking to Churchill:

Winston, you are drunk, and what’s more you are disgustingly drunk.

Churchill:

My dear, you are ugly, and what’s more, you are disgustingly ugly. But tomorrow I shall be sober and you will still be disgustingly ugly.

References:

Rapier wit is slightly different from witty: there's a (sharp) rapier in mind.

Rapier wit:

ability to deliver witty and cutting remarks

A rapier is a very thin sword with a long, sharp point.

As in: (for a single word)

Person A: "I can't bear fools."

Person B: "Apparently, your mother could!"

Person A: "Ouch ... you are quick."

quick OED

Of a person: mentally agile; prompt to think; of ready wit.