"Bring it on!" Kaido roared, refusing to back down as he swung his massive mace to meet her.
BOOM!
Above the sky, lightning crackled and thunder rolled as shockwaves swept outward. When the two spiked clubs collided, it became clear that Yamato's strength still lagged behind Kaido's. Before long, her expression turned strained under the pressure.
"Kaido! Do you have any idea how many people in Wano live in misery every day because of your selfishness?!" Ace suddenly materialized above Kaido, thrusting his spear downward with a thunderous roar.
Faced with Ace's intervention, Kaido was forced to take the situation seriously.
"Hah!" With a violent shove, Kaido sent Yamato flying back. He twisted his body to dodge Ace's strike, swinging his mace in a wide arc in the same motion.
Ace threw up an arm to block.
CRASH!
The collision between flesh and iron sent bolts of dark red lightning racing across the sky above Onigashima. The fighters below could see the atmospheric displacement with their own eyes.
Though the enemy had superior numbers, the tides of battle had stabilized with the arrival of the Straw Hats, Kid, and Law.
King, observing from the fray, was more than happy to let the masked CP agents deal with the Straw Hat crew. However, the World Government weren't the only ones who viewed Nico Robin as the key to the ultimate treasure—the Beast Pirates were equally determined to claim her!
Seeing an opening, King decided to thin the ranks of the Straw Hats first, diving straight toward Chopper and Usopp.
"Eek!!"
Usopp turned pale with fright, unleashing a barrage of Pop Greens and ammunition at King. However, King wove through the projectiles with effortless grace.
In an instant, King was looming over Usopp, his talons ready to strike, when a streak of blue and yellow flames intercepted him.
CLANG!
Whir... Azure flames flickered and rose as Marco the Phoenix slowly manifested before them.
"Why don't you let me keep you company, King of the Beast Pirates?" Marco said, his lips curling into a slight smirk.
"Marco, First Division Commander of the Whitebeard Pirates..." King's expression turned grave.
"Hah!" Marco put strength into his legs and snapped a kick toward King's face. King met it with a heavy punch.
BOOM!
The impact sent a fresh wave of air rolling over the battlefield. The landscape of the war was shifting by the second; Kenshin, Locke, and Ann had also reached the rooftop of Onigashima to join the fray.
At the summit of Onigashima, the three warriors surrounded Kaido.
"Kaido!" Luffy's feet slammed into the ground. In his Gear 4: Snakeman form, his speed was as fast as a lightning strike.
"Gum-Gum... Jet Culverin!"
His dark red arm snaked through the air like a living serpent, hurtling toward Kaido. Kaido tilted his head slightly, narrowly evading the fist, but the arm suddenly banked at a sharp angle, looping around to strike from behind with relentless force.
"What?!" Kaido gasped. Just as he tried to dodge again, the fist changed direction once more.
With no room left to maneuver, Kaido was forced to cross his arms in front of his chest to brace for the impact.
POW!
The punch landed square. Kaido's feet skidded back a full meter across the stone, a stinging pain radiating through his forearms.
"Looks like it's working pretty well..." Luffy grinned.
The combination of Gear 4, Advanced Armament Haki, and Future Sight was devastating. While the hit looked simple, only Luffy knew the sheer level of difficulty required to land a clean blow on a Yonko.
"How is this possible?" Kaido was genuinely surprised.
In his estimation, while Luffy was strong, he shouldn't have been able to bypass his scales without the use of Conqueror's Haki coating. And yet...
Luffy's rate of growth during the heat of battle was enough to make anyone stare in awe. Even Ace was secretly shocked. Luffy's evolution always manifested through the physical act of fighting; asking him to "study" was practically a death sentence. It was normal for him not to understand a word of theory.
But if he saw it, he could do it. Luffy was born to learn through his physical senses. Theory meant nothing to him.
That was Luffy!
"Ace's brother, let me lend you a hand!" Yamato kicked off the ground, putting every ounce of her strength into a swinging strike.
Simultaneously, Ace moved.
As Yamato's mace descended from above, Ace reached out, coating the weapon in a swirl of his most intense, white-hot flames. With this thermal reinforcement, Yamato's destructive power surged by several magnitudes.
KABOOM!
The maces clashed once more, but this time, they were perfectly matched!
"Impossible!" Snarling with indignation, Kaido poured even more raw power into his arms.
Yamato's feet began to slide backward. In terms of pure physical strength, she was still no match for her father.
"Fire Finger!"
At that exact moment, Ace pressed his fingers together, firing a concentrated beam of heat like a laser directly at Kaido.
With a sharp hiss, a bloody hole appeared in Kaido's chest.
Fire compressed to its absolute limit possessed terrifying piercing capabilities. Even Kaido's "invincible" defense was breached, though the beam didn't pass entirely through his massive frame.
"Ugh!" Kaido groaned. Before he could recover, a massive fist slammed into his jaw.
CRACK!
The punch launched Kaido straight into the sky. Luffy's dark red arms extended further and further, chasing him into the clouds!
The sight of Kaido being sent airborne left everyone below in a state of total shock.
"Lord Kaido!" the Beast Pirates screamed in terror.
What is happening?! How can this be? Lord Kaido was punched into the sky! By who?!
"KAIDOOO!!"
A roar shook the heavens. Luffy kicked off the air using Moonwalk, transforming into a blur as he pursued the Emperor.
His fists became a blur, slender arms piercing the horizon as he unleashed a relentless barrage. The air currents screamed as he pummeled the airborne Kaido.
Bam! Bam! Bam! Bam!
"RAAAAAH!" Luffy screamed, throwing punch after punch.
Kaido's abdomen and face were subjected to a frantic, overwhelming assault.
"No way..." The white-cloaked CP agents watched in a daze.
They knew exactly who that was in the sky: the captain of the Straw Hat crew, Monkey D. Luffy!
He was actually suppressing Kaido!
Has the Straw Hat crew... already reached this level?
The "Legendary Four Brothers."
The thought occurred to them—there were four of them in total, and now all four had ascended to the very peak of the world's power. If these four ever truly united under one banner, the World Government... would be in grave danger.
Cold sweat drenched the CP agents. These four brothers had truly come of age. If they ever decided to set their sights on the World Government... the world would be plunged into absolute, irreversible chaos.
How would the Government respond? Could they even...
No, impossible!
The lead agent shook his head violently, trying to steady his resolve. The World Government held the ultimate hegemony over the world; how could it be shaken by a mere four young men?
"Hahaha... exactly. That's it!"
He tried to convince himself, but as he looked back up at the sky, his confidence wavered.
"Gum-Gum... King Cobra!"
Luffy's arm, crackling with dark red lightning, coiled and twisted through the air multiple times before slamming directly into Kaido's chest.
BOOM!!
The massive spatial shockwave rattled the entire island of Onigashima.