Dressrosa Saga

The alliance raids Dressrosa, a kingdom ruled by Donquixote Doflamingo as a puppet king while he supplies artificial Devil Fruits to Kaido. Luffy awakens Gear Fourth, devastating power combining compression with extreme speed. Doflamingo's defeat breaks Kaido's supply chain and establishes the Straw Hat Grand Fleet with multiple allied crews.

The Dressrosa Saga represents the alliance's first major victory and Luffy's most significant power increase since the timeskip. Doflamingo controls an entire kingdom through false authority, profiting from warfare while maintaining the appearance of legitimate rule. The Corrida Colosseum tournament serves as the arc's entry point, gathering powerful fighters from across the world competing for the Mera Mera no Mi — Ace's former Devil Fruit. Among the competitors, Rebecca stands out: the gladiator daughter of the legendary soldier Kyros (known as the Thunder Soldier), she fights with a graceful evasion style and a self-imposed refusal to kill opponents despite the arena's blood sport nature. Her gentle nature creates a striking contrast with the violence demanded of her. Cavendish, the self-styled "White Horse Prince," is another tournament entrant — a former famous prince turned pirate with an unconscious berserker alter ego (Hakuba) that emerges in sleep and slashes everything nearby. Both become crucial allies once Luffy dismantles the tournament's true purpose. The arc's real shock is Sabo — Luffy's sworn brother, thought dead for over a decade — revealed alive and representing the Revolutionary Army, who claims the Mera Mera no Mi in Luffy's stead. The SMILE factory discovery reveals Doflamingo's true purpose: he manufactures artificial Devil Fruits supplied to Kaido's army in exchange for profit and political protection. This economic arrangement demonstrates that corruption involves interconnected systems benefiting multiple parties simultaneously. Luffy's awakening of Gear Fourth marks his greatest transformation since the Marineford War. The form grants immense strength and speed at the cost of rapid exhaustion, limiting its application to short, intense bursts. Law's backstory with Corazon — Doflamingo's younger brother who secretly worked against him to protect Law — reveals that personal history with the crew's allies runs deeper than any tactical alliance. Doflamingo's actual nature becomes clear: he's a former World Noble who abandoned his privilege but retained the authority and connections wealth provided. His defeat requires breaking governmental systems enabling his operations, not merely overpowering him directly. The arc's conclusion establishes the Straw Hat Grand Fleet — a coalition of pirate crews led by Cavendish, Bartolomeo, and others — pledging loyalty to Luffy. This expansion of power structure demonstrates that his influence extends far beyond direct crew membership.