Kaidou plans to move his base to the Flower Capital, transform Wano into a pirate nation rechristened as New Onigashima, and have his "son", Yamato, replace Kurozumi Orochi as shogun. All citizens of Wano, including those of the capital, would be converted into slaves in order to provide additional labor for further industrialization of the country. Kaidou, together with Big Mom, also plan to find the Ancient Weapons and One Piece, starting the "final war" against the World Government and its new power.
In preparation for the announcement, Kaidou requested that the Tobiroppo find Yamato.
Kaidou announced this project during the annual Fire Festival held at Onigashima as Kozuki Momonosuke was about to be executed. When Orochi objected to the declaration of his territory being annexed, which was a violation of the terms of their alliance, Kaidou swiftly beheaded him, effectively ending their twenty-five years of partnership. Kaidou then threatened Orochi's subordinates, offering them a chance to join the Beasts Pirates or risk being punished with death. Without hesitation, they swore loyalty to Kaidou.
During the raid by the Ninja-Pirate-Mink-Samurai Alliance, Kaidou proceeded to raise Onigashima from its spot at sea in order to physically transport it to the Flower Capital and drop onto the shogun's castle. Big Mom pointed out that pulling such a maneuver in the middle of the Fire Festival would naturally lead to a huge number of casualties, which Kaidou laughed off since replacing the dead with slaves was a triviality to him. Furthermore, in order to find the One Piece, Nico Robin, the Archaeologist of the Straw Hat Pirates, and possibly the only person alive who knows how to read the Poneglyphs, was requested to be captured alive.
During the subsequent fights, Kaidou's control of the Flame Clouds began to weaken, causing the island to crumble and threatening to drop the island, which would detonate the explosives in the Armory.Kozuki Momonosuke, who was unable to generate enough Flame Clouds that could hold the island aloft on their own, instead opted to create a single loop on which to pull, slowing the island's movement and safely guiding it toward the ground. When Kaidou focused his efforts into countering Luffy's Gomu Gomu no Bajrang Gun, his Flame Clouds disappeared completely and the island began to plummet. However, in that moment, Momonosuke succeeded in generating enough Flame Clouds to catch the island and brought it safely to the ground on the outskirts of the Flower Capital. Luffy's final attack also sent Kaidou crashing into the ground and plummeting deep beneath the surface.
The Alliance cheers over the victory while the Beast Pirates were thrown into a panic and disbelief that their all-mighty leader was finally defeated. Momonosuke’s decides to postpone opening Wano’s borders to the rest of world. With Kaido and Big Mom both in a pool of magma, it made a chain reaction causing a volcanic eruption where Onigashima one was signifying their defeat  Momonosuke then goes to the Fire Festival to reveal that that Orochi and the Beast Pirates will no longer terrorize the country and claims his rightful place as shogun. Everyone across Wano cheers in glee over Wano finally being saved. Filled with fear, many Beast Pirates are seen retreating because their crew no longer had any control over Wano.