One Piece Movie 14: Stampede - Episode — 1

: "Special Edition! The Strongest Bounty Hunter, Cidre".

You can find the movie and its prequel episodes on major anime platforms: One Piece Movie 14: Stampede - Episode 1

: The film features massive fan service, bringing together the Straw Hats, the Worst Generation (including Law and Kid), the Marines, and members of the Revolutionary Army like Sabo to take down Bullet. Where to Watch : "Special Edition

While is a standalone feature film rather than an episodic series, there are specific "prequel" episodes in the main anime and a primary plot for the movie itself that match your interest. Prequel Episodes (The "Carbonic King" Arc) Where to Watch While is a standalone feature

The movie was released in 2019 to celebrate the anime's .

: The real threat is Douglas Bullet , a legendary former member of Roger’s crew known as the "Demon Heir". He uses his Gasha Gasha no Mi (Union-Union Fruit) to combine inanimate objects into a massive mechanical colossus.