Gear 4th Luffy |link|

Gear Four serves as a turning point in One Piece for several reasons:

Unlike his previous forms, Gear Four renders Luffy unable to stand still. He must constantly bounce, utilizing the stored potential energy to launch attacks at speeds previously impossible for his size. This "bouncing" nature makes him a difficult target to hit and allows him to change trajectory mid-air, a feat that baffled opponents like Doflamingo. gear 4th luffy

Tankman is situational, requiring Luffy to be full to bursting, but it represents the ultimate defensive application of Gear Four. It proved that Luffy’s rubber body could counter almost any physical attack if he had the mass to absorb the impact. Gear Four serves as a turning point in