After blocking the 'Diamond Arrow', Luffy grimaced for a while, clenching his fists. "Momo asked me for help, and you, the obstacle in my path, I will defeat you!"

Kaido sneered, "Kid, I admit you have some strength. After running away for so long, you actually managed to fight me to a standstill. You have a certain status on the sea, but if you want to beat me, you're still a long way off!"

"Rubber, rubber..."

Without saying a word, Luffy sprang up with his feet, his body soaring into the air. Then, he tucked his legs into his thighs and kicked hard at Kaido.

"Rhino howitzer!"

Those feet sprang out with domineering force, their elasticity possessing unparalleled speed and power.

Kaido was startled and held his spiked club upright in front of his chest to block the extremely fast kick.

Bang!

The combination of Conqueror's Haki and Armament Haki caused their incredibly fast, powerful kicks to collide with the spiked club in mid-air, adding even more gloom to the already overcast sky above the hole, and splitting the sky into a line directly above their heads.

"Heat Breath!"

After Kaido blocked the attack, he opened his mouth and spewed out a jet of fire that shot straight at Luffy's body in mid-air, causing a huge explosion that impacted the entire room.

What's strange is that this attack, powerful enough to vaporize a mountain, exploded inside the house, only causing the surrounding walls to vibrate.

"Rubber, rubber..."

A sound rang out from the explosion, and Luffy's massive, inflated body suddenly shot out, one fist retracting into his upper arm like a spring, aimed at Kaido, and shouted: "JET Snake Cannon!"

An even faster punch than before was launched, striking Kaido squarely in the face just as he opened his mouth to spew. The force of the punch caused Kaido to grunt and fall backward with his massive body, crashing heavily onto the floor with a tremendous tremor.

"cough!"

Kaido coughed violently, spitting out a small spurt of blood, and collapsed to the ground, panting heavily.

My stamina is starting to wane...

He shook his head, straightened up halfway from the ground, stared intently at Luffy's figure bursting out of the explosion, and grinned, "I can understand blocking lightning, but why can it also block flames!"

Luffy grinned, showing his bright white teeth, and said, "Hehe, I won't tell you!"

"Then just die!"

Kaido opened his mouth again and spewed out a ball of hot breath straight into the sky. Luffy did not take the hit head-on this time, but twisted his body and dodged it in the air. His forearm suddenly expanded, like the arm of a giant, and then quickly retracted inward. Black lightning shot out from his fist and he punched out.

"Rubber Rubber - Great Ape King Gun!"

Bang!

It was a muffled sound from being compressed to its limit and then suddenly released. Kaido's pupils shrank, and he spun his spiked club twice in his hand, bringing with it a black lightning bolt, as well as swirling lightning and wind, before swinging it directly at the fist.

"Thunderbolt and Wind Strike!!"

Boom!!!

The fist and the stick made contact again, causing the room to shake violently. Shockwaves radiated outwards from the center of their attack, striking the surrounding walls and causing them to tremble.

"roar!!"

After a brief stalemate, Kaido's arm swelled up, and he thrust his spiked club forward, deflecting the fist and striking Luffy hard in the abdomen with a burst of lightning and fire energy.

That blow caused Luffy's abdomen to cave in, and he groaned, his movements becoming somewhat sluggish. In that instant, Kaido on the ground flicked his dragon tail, his entire body shooting towards Luffy, his spiked club carrying black lightning as it slammed down, striking Luffy's face hard.

"Thunderous Eight Trigrams!!"

"Rubber Rubber - Second Great Serpent Cannon!"

Just then, Luffy clenched his other fist and launched it forward, slamming it hard into Kaido's face, deforming his features.

Thump!!

With a loud crash, both of them flew downwards and crashed heavily onto the floor.

The moment he landed, Luffy sprang up, clenched his fists, and shouted with a resolute expression, "Kaido!!"

"That damned guy!"

Kaido stood up, gripped his spiked club 'Eight Precepts' tightly, steadied himself, and gritted his teeth, revealing a sinister grin: "You really get my blood pumping!"

That's really heartbreaking.

Just as Kaido was about to raise his club to continue the attack, he and Luffy both froze and looked in the direction from which the sound came from.

At the exit of the room, a person appeared out of nowhere. He was chewing on a cigar, letting the smoke swirl around his face. He stretched out his arm and tapped his fingers on the wall, making a very elastic snapping sound.

"Has it awakened? No wonder there's been no movement in the room for so long. Otherwise, this castle should have been destroyed long ago."

As the smoke cleared, a familiar face was revealed. He looked at Kaido and said, "Long time no see. When I saw you again, I never imagined that you would be fighting the Straw Hats so fiercely."

"Kuro?!"

Kaido's face darkened: "When did you arrive?!"

Kuro smiled faintly: "It's been a while. I've been watching you guys because you're so focused on the fight. It seems you've used up a lot of energy; I didn't even notice."

After the castle was lifted into the air, the atmosphere of battle diminished considerably, which confirmed to Kuro that Linlin was not in the castle. Her presence was gone after the castle took off, replaced by Kaido's aura, which led him to this location.

As for Momonosuke and Orochi, he had no interest in watching them.

But here, he felt something was off after he arrived.

It had been a long time since he'd seen them. When he arrived, he saw the two of them brutally fighting each other. Judging from their condition, they had exhausted a lot of energy, and the wounds on their bodies indicated that their previous battle had been quite intense.

Based on Kuro's experience, Kaido has already gone all out, and he's been fighting Straw Hat Luffy for so long without success. He's almost exhausted and has turned into his human-beast form.

The most outrageous one is Straw Hat Boy!

"I really didn't expect this..."

Kuro looked at Luffy, exhaled a puff of smoke, and said, "It's been a while, and you've actually grown to this level. That attack just now was 'Unified Haki,' right? And there was also Conqueror's Haki wrapped around you, and the elasticity of this room... You've awakened your abilities, haven't you?"

He personally witnessed Kaido unleash a Thunder Bagua attack, imbued with Conqueror's Haki, slamming it into his face. Despite such an attack, Luffy didn't fall down, demonstrating a level of resilience comparable to Zoan-type Devil Fruit users.

Why are you, a Paramecia type, so durable? Even rubber shouldn't be this tough!

"That's right, I've learned 'Muramasa' and Conqueror's Haki!"

Luffy chuckled, watching as Kuro suddenly tilted his head, staring at him for a long while before focusing his gaze on the smoke Kuro exhaled, a look of sudden realization dawning on him. He clapped his left fist against his right palm and exclaimed, "What?! You're an incense burner?!"

Kuro's calm expression instantly crumbled, and with veins bulging on his forehead, he roared at Luffy, "My name is Kuro! You only just recognized me, you brat!"