One Piece: I will become stronger by checking in

[Ding! Check-in at Marineford successful. Sun Wukong Form upgrade initiated. Demon Form consumed. Sun Wukong Form evolution stage one unlocked—Stone Ape Form!]

[Stone Ape Form: Transforms the user into a Stone Ape, granting immense attack and defense power at the cost of reduced speed.]

The moment the system's voice echoed in his mind, Kai's eyes lit up with surprise. He'd been in this world for a while now, and his Devil Fruit abilities had been steadily improving, both through the system's upgrades and his own relentless training.

Today, after countless battles and a little help from the system, he'd finally taken the first step toward becoming the Great Sage Equal to Heaven. Sure, it was just the first step, but Kai was confident that, with time, he'd unlock the full potential of his Devil Fruit.

The only downside? The Demon Form was gone. While the Stone Ape Form was undoubtedly stronger, Kai couldn't help but feel a little... apprehensive about its appearance. Just the name alone made him think it might not be the most aesthetically pleasing transformation.

Well, if I get stronger and uglier, that's just the price of power, right? Kai thought, shaking his head. He'd deal with it when the time came.

For now, he turned his attention to the battlefield below. Nami was already guiding the Ark Maxim to descend slowly.

Whitebeard, standing on the deck of the Moby Dick, looked up at Kai with a mix of curiosity and relief. He'd heard about the events in Water 7. If the reports were true, Kai's presence would be a massive boon in rescuing Ace.

After all, even Whitebeard himself couldn't take on multiple Admiral-level fighters at once. Kai's ability to create clones of himself, each nearly as strong as the original, was a game-changer. While Kai's base strength might not match Whitebeard's, the sheer numbers made him a force to be reckoned with.

Thankfully, Kai was on their side. Otherwise, this battle would've been even more of a nightmare.

Everyone's eyes were locked on Kai and his crew as they descended. Even the prisoners on the execution platform were watching intently.

Franky, tied up and awaiting execution, stared at Kai with a mix of shock and hope. He knew the caliber of the people surrounding him—Admirals, Warlords, and even the Five Elders. If they were wary of this young man, then maybe, just maybe, he had a chance of survival.

What kind of guy is this? Franky wondered. He'd been living his life as a shipwright in Water 7, minding his own business, when suddenly he'd been dragged into this mess. He didn't even know why he was being executed. Sure, he had the blueprints for Pluton, but how had the World Government found out? Only two people knew about it—himself and Iceburg. And Iceburg would never betray him.

Franky sighed. If he survived this, he'd have one hell of a story to tell.

Next to Franky, Ace was equally stunned. Garp had mentioned Kai during one of their talks, but Ace hadn't expected the guy to be this powerful. He'd been captured because of his own recklessness, and now the Whitebeard Pirates were risking everything to save him. The guilt weighed heavily on him.

He glanced at Whitebeard, his father figure, who was already in poor health. If anything happened to Whitebeard because of this, Ace would never forgive himself.

On the other side of the execution platform, Robin's eyes filled with tears as she looked at Kai and the others. She remembered Saul's words from her childhood: "One day, you'll find friends who will protect you."

And then there was Kai's promise: "No matter what happens, we'll never abandon you. I'll always have your back."

Robin's heart swelled with emotion. She knew exactly how dangerous it was for them to come here. They were risking their lives for her.

Kai's voice cut through the tension, calm but resolute. "Robin, don't worry. I'll get you out of here."

The words echoed across Marineford, silencing the battlefield for a moment.

Then, in a flash of light, Kai disappeared from the Ark Maxim, reappearing in an instant beside Robin.

The battle was about to begin.