One Piece: I will become stronger by checking in

The laughter of the two men echoed across the battlefield, leaving those around them bewildered. Weren't they on edge just moments ago? Why were they laughing like old comrades now?

"He truly lives up to the title of the strongest in the world. His courage is beyond comparison with ordinary men!" Kai said with a grin, looking at Whitebeard.

Whitebeard returned the smile, his booming voice carrying across the battlefield. "Brat, you really surprised me. To have such a level of Conqueror's Haki at your age... Even that red-haired kid was probably far behind you back then!"

"Honestly, I think so too!"

"Gurararara..."

The two burst into laughter once more.

After a while, their laughter gradually faded. Kai turned his gaze toward the Five Elders and spoke calmly, "Those five old geezers have finally shown up. How do you think we should handle this?"

"What else? We fight! Ace is my son, and he's getting out of here. I'll just need to clear the path for him!" Whitebeard's voice was steady, his conviction unshakable.

"Exactly!" Kai nodded.

Now that the war had begun, there was no turning back. Stopping it was no longer an option—this battle was inevitable.

Standing on the bow of the Moby Dick, Kai looked down at the battlefield. The mid- and low-tier combatants of both sides were already locked in a chaotic melee, neither gaining a clear upper hand.

But the true powerhouses had yet to make their moves.

Kai shifted his gaze toward the Thousand Sunny and saw that Luffy and his crew were no longer aboard. Instead, they had already charged into the battlefield below.

Seeing this, Kai couldn't help but smile like a proud older brother. Luffy, Zoro, and Sanji had all reached at least Vice Admiral-level strength. Even in this grand battle, they were no small players.

And it wasn't just them—Usopp and Nami, who had only recently eaten Devil Fruits, were proving their worth as well. The two of them were tearing through the battlefield, taking down Marines left and right.

With an exhilarated grin, Usopp shouted, "Now this is a battlefield fit for warriors of our level! All that training finally paid off!"

"Right?!" Nami, surrounded by crackling lightning, unleashed a devastating storm upon the Marines charging toward her.

For these two, the average Marine foot soldiers were no longer a threat. It was proof that there were no useless Devil Fruits—only weak users. A powerful fruit in the right hands could make someone formidable in a short time.

For instance, the difference between an ordinary Zoan and a Mythical Zoan was like night and day. Look at the world's strongest fighters—how many of them had Devil Fruits that weren't monstrous? If fruits were all equal, why did the Five Elders each possess a Mythical Zoan?

Anyone with a brain could figure it out.

Elsewhere, Robin, Chopper, and Brook were also locked in battle against the Marines.

Compared to Nami and Usopp, their fights were less flashy. After all, their abilities didn't come with spectacular visual effects.

Especially Chopper and Brook—if you said they had abilities, they did. But if you said they didn't, well… they certainly didn't look like it.

Yet their impact was undeniable.

A squad of Marines, upon seeing Brook, completely lost their nerve.

"A skeleton... A talking skeleton?!"

"Can someone explain to me why a skeleton is alive and fighting?!"

"Mom, I must be dreaming!"

"This is terrifying!!!"

"Yohohoho~ Don't be afraid~~~!" Brook's laughter rang out as he chased the screaming Marines across the battlefield.

Kai's eyes then shifted to the pirates he had freed from Impel Down's Eternal Hell. His voice was calm but commanding: "It's time to fulfill your promise."

Jinbei had already joined the fight, and Crocodile was keeping his sharp eyes on the battlefield. Kai didn't even need to guess—he knew Crocodile was watching Whitebeard, not him.

As for the other pirates, they stood idly on the deck, acting as if the battle had nothing to do with them.

Kai wasn't about to let that slide. He hadn't freed them just so they could enjoy the fresh air.

And as he had said before, anyone who refused to honor their agreement would be joining Byrnndi World in the afterlife.

To Kai, these pirates were useful, but not indispensable. Even a single clone with 90% of his strength could wipe them out.

This was why, when he sensed another powerful presence back in Impel Down, he hadn't invited them.

If his guess was right, that presence had been Douglas Bullet.

Kai acknowledged Bullet's strength, but his personality made it clear—he was the type who wouldn't submit to anyone.

Kai had no interest in convincing him.

Bullet was strong.

But Kai was stronger.

The freed pirates hesitated for a moment, displeased but wary. They remembered what had happened to Byrnndi World. And after witnessing the Conqueror's Haki clash between Kai and Whitebeard, they decided they weren't about to test their luck.

One by one, they leaped into the battlefield, carving a bloody path through the Marine ranks. The foot soldiers stood no chance against them.

Seeing this, Sengoku scowled, cursing under his breath. "Damn Kai... he really freed those criminals. Doesn't he understand how dangerous they are?!"

Every pirate imprisoned in Eternal Hell was at least Vice Admiral-level or higher. Letting them loose on the battlefield was a nightmare for the Marines.

Sure enough, as the chaos spread, the Marine Headquarters' Vice Admirals sprang into action, rushing in to intercept the new threat.

Everyone was finding their opponent. The battle was reaching a fever pitch.

Kai watched the carnage unfold with an indifferent expression. Right now, the two sides were evenly matched, but Marineford still held a slight advantage.

After all, the Warlords of the Sea had yet to make their move.

As if responding to Kai's thoughts, Doflamingo suddenly leaped from the wall, landing in the thick of battle. The ground beneath him twisted into countless strings, forming a deadly battlefield in his favor.

At the same time, Mihawk silently unsheathed his sword.

The true battle was about to begin.