Previous story
After the battle of the Straw Hat Pirates Alliance against the alliance between Kaidou and Big Mom and their entourage on Onigashima began, the Nine Akazaya confronted the same emperor on the roof of Kaidou’s castle. In order to take part in this decisive battle, Luffy directly attempted to make his way to the roof to assist his nakama against the mighty enemy.
After finally reaching his destination, however, he found that he, along with Zoro, Trafalgar Law, Eustass Kid, and Killer, had arrived too late, as Kinemon and company lay already defeated and covered in blood. In tears, the samurai was ashamed of his defeat and asked Luffy to take the Akazaya’s burden in his place and complete their task of freeing Wano Country. Luffy didn’t hesitate and immediately complied, using Trafalgar Law’s devil powers to get the samurai out of harm’s way.
The fight
Enraged by the Straw Hat captain’s defiance, Kaidou finally grabbed his weapon first and attempted to deliver a mighty clubbing blow to Luffy, which the rubber boy was able to dodge with lightning speed. Finding himself in the sky above Kaidou, he instead revealed a new technique of his own: the Gomu Gomu no Red Roc. In his Gear 3 mode and with the aid of his armor haki, he delivered a flaming and devastating blow to the Emperor’s face, knocking even the “World’s Strongest Creature” to the ground for the time being.
Beginning – Two powerful alliances
This even horrified Charlotte Linlin, who angrily summoned her homie Prometheus to use his Heavenly Fire, but at that moment Zoro revealed that he had learned Kinemon’s technique “Homura Saki” and used it to split the living sun into two.
At the same time, the resurrected Kaidou drew his club and delivered a powerful blow to Luffy, similar to his former fight against the rubber boy in Kuri, with his attack “Raimei Hakke”, which the straw hat was able to survive relatively unscathed this time, however. He was again saved from the following clubbing blow by his alliance partner Law, after which the two former Supernovae ended up at Eustass Kid.
Against these three opponents, Linlin immediately mobilized Prometheus again, who hit the pirates with his Heavenly Bonbon. Meanwhile, Zoro and Killer also joined forces, attacking Kaidou with their “Rengoku Oni Giri” and “Zanshu Claw” techniques, which left the Emperor rather unimpressed. Hitting Luffy, Law and Kid also remained largely unsuccessful, so the three also went for a combo of their attacks “Gomu Gomu no Kong Gun”, “Punk Vise” and “Tact”, which powerfully rammed Kaidou to the ground. Therefore, the Emperor finally transformed back into his dragon form and then faced his five challengers again along with Big Mom. While everyone was now finally ready to fight, according to Kaidou, it would be the winner of this battle who would come closest to being King of the Pirates.
Emperor vs. New Generation – The Supernovae Storm Ahead
Following these words, the “most powerful creature in the world” immediately resumed the fight. As he had done before against the Akazaya, he hurled his blade wind “Kaifu” at his challengers, which briefly destroyed Kid’s metal arms, but was blocked by Zoro. Luffy used this moment to give Kaidou a hard hit with his “Gomu Gomu no Kong Rifle”, which in turn gave Kid the time to renew his metal body. The “Captain” then went for his “Slam Gibson” technique, which sent the giant dragon crashing to the ground. Law used the confusion of his opponent for his attack “Gamma Knife”, which made Kaidou cry out in pain.
But since the emperor was not to be subdued by this either, Killer joined the fight and landed a powerful blow by means of his “Kamaa Sonic”. Suddenly, a mighty lightning bolt descended from the sky, hitting Killer in full force and being sent out by Big Mom, who realized in the same breath that they must have underestimated their enemies. Before Kaidou could follow up against Killer, however, Luffy stepped up again and rammed the very same aside with his “Gomu Gomu no Rhino Schneider”.
The Emperor tried to fight back with his “Boro Breath”, but Zoro had Law catapult him into the air to once again slice the Zoan user’s Fire Ode with his “Homura Saki”.
As a result, he continued to showcase the powers of his new sword via his “Hiryū Kaen” attack, which missed Kaidou but left the Emperor feeling the aura of Kozuki Oden in shock. That’s when Big Mom intervened again with the help of Zeus, letting loose her technique “Tenman Daijizai Tenjin”, a veritable hail of powerful lightning.
These seemed to wreak havoc on Luffy as well as Zoro and Law, but the Empress was horrified to discover that her attack was ineffective against the Straw Hat’s rubber body. Instead, the rubber boy took to the air once more to retaliate for the blow to his nakama, which Kaidou tried to prevent with his Boro Breath, but Luffy easily survived that one as well, much to the incomprehension of his opponents. Now on top of Kaidou, he launched his devastating “Gomu Gomu no Kong Gatling”, which hit the dragon with full force.
 Killer Attacks Kaidou… |  …but Big Mom counters |  Zoro’s mighty sword thrust misses its mark |  Luffy hits Kaidou devastatingly |
Kaidou Seeks Turn – Luffy and Zoro’s New Strength
After Luffy was able to give Kaidou dozens of heavy hits with his Gatling, the side effects of his Gear 4 finally showed, forcing him to change back for the time being. Unable to use a Haki for the next ten minutes, Zoro grabbed his captain to keep him safe while Law, Kid, and Killer tried to keep the two emperors busy. In the process, the former delivered a painful “Counter Shock” to Big Mom, while Kid and Killer tried to pounce on the supposedly weakened Kaidou, but the latter revealed that he was far from finished and beat back the two former Supernovae with his “Tatsu Maki”.
The latter also catapulted Luffy out of Zoro’s arms, whereupon the dragon took the opportunity to grab the rubber boy with his mouth. Therefore, Zoro, strengthened by Oden’s King Sword Enma set to his attack “Kokujō: O Tatsu Maki”, which was able to penetrate even the zoan user’s skin. Now understanding that the swordsman’s power came from the sword of the former prince of Kuri, Kaidou countered with an even stronger version of his whirlwinds, the “Tatsu Maki Kaifu”. After this attack was over, the roof of the castle was completely in ruins and everyone involved was already clearly battered. Still, to add a new twist to the fight, Kaidou unceremoniously decided to transform into his hybrid form.
 Law stops Big Mom |  Kaidou reveals his power over the forces of nature |  Zoro can actually hurt the giant dragon |  Kaidou’s mighty whirlwind |
The Plan – Separate the Emperors
After doing just that, Killer remarked that they had hardly harmed the two Emperors with their attacks, and therefore they had better fight them separately. Luffy had recovered by this time, and countered this suggestion by saying that their attacks must have been quite painful, since even Kaidou and Big Mom were only human. Nevertheless, he too agreed to a plan to separate the opponents, for which Kid in turn wanted to use Law’s devil powers. The latter, however, only replied that the Emperor’s Haki was too powerful to get close enough to them. Though the alliance seemed to have quickly come up with a new plan to carry out their idea, it was Kaidou and Linlin who first launched a combo attack. Wielding their two weapons, they created an enormous blast of energy towards their enemies using their technique “Hakai”. This discharged far beyond the borders of the flying island, but Zoro faced it with all the power of his mighty swords and thus protected his comrades-in-arms from worse. Luffy immediately used this opportunity to swing himself into the air and attack Kaidou, who, however, easily dodged his stretched arm.
The rubber boy, however, interpreted this behavior as evidence that the emperor must have been hit hard by his blows last. Furious at this conclusion, Kaidou summarily turned his club and rammed Luffy devastatingly into the ground with his “Kosanze Ragnaraku” attack. Meanwhile, the others turned their attention to Big Mom, with Kid suddenly forming a box of metal pieces. Using his “Shambles”, Law in turn transported Zeus into this dungeon, clearly shocking Linlin.
Confused by this move, Zoro and Killer thoughtfully launched a surprise attack towards the Empress, the former using his new skills to slice Prometheus into several pieces and the latter using his blades to effortlessly deal with Napoleon. Dismissed of their homies, Kid immediately fired his “Punk Pistols” at Linlin, but she was completely unimpressed with the attack and forcefully knocked the former Supernovae to the ground in return. However, seeing a laugh on the latter’s face after this counterattack, it turned out that “the Captain” only wanted to get close enough for his technique “Repel”.
Carried by flying pieces of metal, he dispatched Linlin with it in short order as Law also strode over and used his “Tact”, additionally hurling a large chunk of rock at the Empress. Not realizing at first what the calculation behind this joint attack might be, Linlin finally realized that she had been catapulted over the island’s border by the two projectiles and was now in free fall towards the open sea; the captured Zeus, however, could not come to her rescue this time.
 The powerful combo of the two emperors |  Kaidou hits Luffy hard |  Zoro uses his Homura Saki with three swords |  Kid lets himself be met to implement plan with Law |
While the empress plunged to her supposed death, Kaidou attacked Zoro in order to free Prometheus from his captivity. Although the swordsman was saved by Law’s devilish powers, Prometheus also freed himself, who finally saved his mistress from drowning. Law immediately used the opportunity to deliver a painful “Injection Shot” to Kaidou, after which he himself was thrown away by the latter’s club. While the other three continued to take care of Kaidou, Kid and Killer Big Mom rushed in to continue the fight against them separately.
Seeing the unconscious Luffy lying on the ground, Kaidou was about to finally kill him when Zoro spoke up and announced that he was only capable of one last attack. To this end, he reinforced his swords, including the mighty Enma, with Haki and inflicted a gaping wound on Kaidou with his “Hell Hakkei” attack, whereupon he collapsed, exhausted. Although the emperor had been hit hard in the meantime, he still managed to knock Law out with his technique “Reimei Hakke”. Considering himself the winner, Kaidou was horrified to see that Luffy had risen again. The straw hat now told about the ability of “flowing” Haki, which he had tried to learn from Hyogoro.
Kaidou laughed about how Luffy could never be one of the few people in the entire world to master this technique, and so he set off for another clubbing blow, which the rubber boy blocked effortlessly with his foot, however, and without touching the weapon. In a flash, he also counter-attacked by flinging himself towards Kaidou and delivering a devastating punch to the pit of his stomach, followed by a powerful hook to the chin that made even the “most powerful creature in the world” spit blood and fall to the ground.
All of these hits came without direct physical contact, so Luffy now thought to his teammates that he could continue the rest of the battle alone.
 Zoro’s Last Stand |  Law is also defeated |  Luffy finally masters the “flowing” Haki |
Using his new abilities, Luffy was able to engage Kaidou in a brief, evenly matched battle, but his strength was ultimately insufficient to withstand him indefinitely. So it was only a short time later that Kaidou was the only one left on the rooftop, while Luffy, seemingly defeated and unconscious, plummeted down from the flying island of Onigashima towards the open sea. While the Emperor paid tribute to the Straw Hat for the tremendous progress he had made in the short time since their first encounter, he also noted that the rubber boy simply wasn’t ready.
He then had Bao Huang announce Luffy’s defeat throughout the castle.
Shortly after, however, Momonosuke noted via a Mary that Luffy was defeated, but not dead, as he could still hear him.
