The chapter showcased two signature moves of Boundman:
Luffy adapts Gear 4 into different versions based on the combat need:
Luffy realizes he can’t move fast enough in this bulky form. He kicks the air repeatedly (similar to Geppo/Sky Walk) to propel himself, using his inflated, Haki-coated legs as shock absorbers and thrusters. gear 4 chapter
Maintaining the Haki coating on such a massive scale while maintaining the air pressure requires an absurd amount of energy. Luffy mentions early on that he can only use this form briefly because it drains his Haki rapidly. Once the timer runs out, he becomes vulnerable and unable to use Haki for 10 minutes (the famous "Haki recharge" period).
The chapter opens with a massive shockwave hitting the palace. Doflamingo looks confused as Luffy emerges from the smoke, changed. The chapter showcased two signature moves of Boundman:
Before Chapter 784, the situation in Dressrosa was dire.
A homing punch. Because Luffy’s arm is both stretched and coated in Haki, he can curve and redirect the fist mid-flight, tracking a moving enemy. This negated Doflamingo’s evasion tactics. Luffy mentions early on that he can only
Gear 4 represents Luffy’s growth under Silvers Rayleigh.