In One Piece lore, only one in a million people are born with the Color of the Supreme King. But using it is not enough. As Kaido explains in Episode 1028,

[Ep. 870] Whole Cake Island (Katakuri Clash) │ [Ep. 1017] Wano Roof (First Advanced Haki Try) │ [Ep. 1028] Coating the Fist Against Kaido │ [Ep. 1071] Gear 5 Awakening Episode 870: The Mirror World Finale

Luffy first demonstrates his Conqueror's Haki during the Marineford Arc (Episode 388 and 389, and more notably in Episode 391) when he is trying to protect his friends and particularly when he's fighting against Donquixote Doflamingo's subordinate, however the most pivotal and clear demonstration is during the Fishman Island Arc doesn't occur but rather during the Dressrosa Arc.

For most of the series, Supreme Haki is only used to knock out weak-willed enemies. However, the Rooftop Battle in Wano introduces its ultimate, offensive form.

The elusive Supreme Haki has been a topic of great interest among One Piece fans, particularly when it comes to Monkey D. Luffy. Throughout his journey, Luffy has demonstrated remarkable growth in his Haki abilities, eventually mastering his Supreme Haki.

After his two-year training with Rayleigh, Luffy uses Haki intentionally for the first time to take down the Fake Luffy and his crew without breaking a sweat. Massive Display (Episode 554): On Fish-Man Island, Luffy uses Haki to instantly knock out of Hordy Jones' 100,000-man army. Advanced Conqueror's Haki (Episode 1028):

Around the 18-minute mark of Episode 1028, Luffy stares down Kaido. He stops trying to punch with physical strength. Instead, he channels his willpower into his fist. Black, thick lightning (visually distinct from Armament Haki) begins to coil around his arm without him touching anything .

Kaido’s head snapped back, a line of blood trickling from his mouth. He looked down at the young pirate, whose straw hat cast a shadow over his glowing eyes.

Stranded in Level 5 (the Freezing Hell) and severely weakened by Magellan's poison, Luffy releases a desperate wave of Conqueror's Haki to save Bon Kurei from a pack of vicious military wolves.

: During his fight against the Boa sisters on Amazon Lily.

Fans of the series have been eagerly waiting for Luffy to unlock and master Supreme Haki, and the moment finally arrived in a pivotal episode of the anime. The question on everyone's mind is: which episode does Luffy use Supreme Haki?

Luffy clashes with Donquixote Doflamingo . When their kicks meet, black lightning crackles in the air—a visual indicator that two Supreme Haki users are colliding.

If you want to see him use it at its absolute strongest (defeating Kaido), watch .

Experience the epic battle and Luffy's awe-inspiring display of Supreme Haki by watching of the One Piece anime series. Join the adventure and immerse yourself in the world of One Piece, where friendship, power, and excitement await!