The core mechanic of Gear Fourth is described by Luffy as "Muscle Balloon" (Kinniku Balloon). Luffy blows a massive amount of air into his muscular structure rather than his bones. This results in a torso that appears round and robust, with his limbs becoming coated in an incredibly dense layer of muscle.
Note: The transformation was teased at the very end of Chapter 783.
Initially, the form's appearance was polarizing for fans and even laughed at by Doflamingo due to Luffy's spherical torso and constant bouncing. However, its effectiveness was undeniable. In this state, Luffy combines the speed of Gear 2 with the raw power of Gear 3, while his Haki-infused rubber skin becomes durable enough to bounce back Doflamingo’s attacks effortlessly. when do we first see gear 4
Doflamingo was capable of tracking Gear Second’s speed. However, Gear Fourth’s "Boundman" form alters Luffy’s trajectory. By compressing his body into the ground or air, Luffy achieves a chaotic, bouncing movement pattern that is difficult for observation Haki users to predict.
Boundman (or Bounceman) form. This transformation is a sophisticated combination of previous techniques: Muscle Balloon: Unlike Gear 3, where he blows air into his bones, Luffy bites his forearm and blows air directly into his muscular structure. Armament Haki: He coats his limbs in dense Haki to manage the immense internal pressure, resulting in a distinct tribal-patterned appearance. Elasticity & Tension: This form allows Luffy to compress his limbs like springs to launch devastating attacks, such as the The core mechanic of Gear Fourth is described
That’s the moment.
The Genesis of the Bounce: A Technical Analysis of the First Appearance of Luffy’s Gear Fourth Note: The transformation was teased at the very
Monkey D. Luffy unveils this transformation during the absolute climax of the Dressrosa Arc to break the ultimate stalemate against the Warlord of the Sea, Donquixote Doflamingo. The Moment of Reveal: Dressrosa Arc
We don’t just see it when Luffy first uses it. We see it every time he risks himself for his crew.
A punch that can change direction in mid-air to "chase" an opponent. Leo Bazooka: A massive double-palm strike.
On the surface, the answer is simple: Episode 726 / Chapter 784 — Luffy vs. Doflamingo, Dressrosa.