Gomu Gomu no Mi/Gear 3 Techniques, One Piece Wiki

Gear 3 ("Gear Third") is a transformation technique that uses the power of the Gomu Gomu no Mi to inflate a body part and enhance the strength of the user. It was first hinted at during the climax of the fight between Luffy and Blueno, and first used but not witnessed by anyone (including the viewer), to knock down a steel door in Enies Lobby. It was first fully seen in Luffy's fight against Rob Lucci. Luffy corks his mouth with his thumb, bites into his thumb joint (making a small opening) and

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