This is the load-bearing visual grammar of Luffy’s entire Gear vocabulary, not a one-off echo. The composition is fixed: (1) Luffy bites a body part, (2) blows, (3) a near-silhouette black mass balloons out with radiating impact/speed lines and an oversized SFX, (4) the technique is named in a jagged ”___ Balloon!!!” balloon. Gear Fourth’s “Muscle Balloon” (0784) restages Gear Third’s “Bone Balloon” (0421) beat-for-beat, swapping bone-inflation for muscle/torso-inflation.
The root of this grammar predates the Gears entirely — it traces to the Gum-Gum Balloon inflate-to-a-sphere panels of Ch. 15 (inhale → name-call → inflate), already flagged in that chapter’s notes as “the foundational silhouette for the entire Gear vocabulary.” Gear Second (0387) is the deliberate variant that breaks the mold — it substitutes a blood-pump (“BLOOMP”) and rising steam for the bite-and-balloon, which is precisely why Gear Two and Gear Three/Four read as different power-axes on the page.
What to watch for in future Gear-tier debuts: any time Oda wants a new Luffy transformation to feel like a Gear escalation (rubber-inflation lineage) rather than a Haki/speed axis, expect this exact bite → balloon → ”___ Balloon!!!” panel grammar to recur. A Gear debut that omits the balloon panel is signaling a different mechanical family.
