Marineford

Marineford, also known as Marineford Arc or the Paramount War, is a major event in the "One Piece" series where the Marines, the world's military force, launch a massive assault to capture Ace, a powerful pirate and Luffy's brother. The battle takes place at Marineford, the Marine headquarters, involving pirates, Marines, and allies, resulting in significant loss of life and shifting the balance of power in the world. It explores themes of loyalty, sacrifice, and the harsh realities of conflict, serving as a pivotal turning point in the series.