Archmage MC said
Well it has massive downsides that pair off well with her fruit.
If you know basic physics and what happens when the body reaches speeds nearing the speed of sound, and what would happen if you went from mach 1 down to 0 kph,, you wouldn't want anyone without some ability to deal with extreme kinetic trauma.
She can teach it to you, but it'll be far less effective and far more detrimental past certain speeds and fusion punch would hurt you just as much as the opponent. lol.
He's still gonna end up asking, and trying. Besides, he can use it with his chains to either shield himself from the effects and/or use it with his weapons, which are made from his chains.
EDIT: Where did everyone go?