Heavy Infighting

Gravity Magic: Heavy Infighting (重力魔法『ヘビーインファイト』) is a Gravity Magic spell.

Description
With an open grimoire, the user moves in close to their opponent and rapidly punches them. The user augments gravity in a way that it simultaneously increases the weight of their fists, making the punches deal more damage while decreasing the weight of it, making the punches faster.

Trivia

 * Infighting, or inside-fighting, is a boxing term for getting in close to the opponent.