when does luffy use gear 2

Monkey D. Luffy first uses Gear 2 in the Enies Lobby arc of One Piece, specifically debuting this form in his fight against Blueno, a CP9 agent. This occurs in anime episode 272 titled "Luffy is in Sight! Gather at the Courthouse Plaza" and manga chapter 387. Gear 2 is a technique where Luffy speeds up the blood flow in his body, enhancing his speed and strength. His skin turns red and emits steam as a result. This transformation enabled him to defeat Blueno and marked a major milestone in his powers. Luffy uses Gear 2 in various battles after that, including against Rob Lucci, Vander Decken IX, Hody Jones (with the Red Hawk attack), and Pacifista units. Gear 2 attacks often combine with Haki for greater effect and include moves like Jet Pistol, Jet Gatling, Jet Bazooka, Jet Hammer, and Jet Migawari. The technique enhances Luffy's strength and speed but initially puts strain on his body, though he manages to mitigate the side effects over time.