High above the clouds of Skypiea's Birka, atop its misty peaks…
Rosinante lay lazily on a recliner, sipping juice that Shaxia had just served, a book resting open on his chest.
Not far from him, in an open space, two small figures clashed repeatedly at lightning speed.
Those two petite silhouettes were none other than Robin and Raqi.
Though it looked like a fierce spar, the attacks were completely one-sided—Robin was on the offensive while Raqi focused solely on defense.
Yet what surprised even Rosinante was how effortlessly Raqi dodged and parried each and every one of Robin's attacks—even the abilities of the Flower-Flower Fruit. It was as if she had already foreseen Robin's every move.
At the same time, Raqi calmly pointed out the flaws in Robin's techniques, giving guidance even as they sparred.
Robin, far from being discouraged, nodded thoughtfully at each correction. The next round, her attacks grew even more refined, more precise.
Since arriving in Skypiea, Robin had been training every day alongside the Bloodsworn Guard's reserve forces.
And every time they returned, Rosinante would personally give her further guidance—and occasionally spar with her as well. Rosinante always believed that strength grew fastest through live combat.
But when it came to sparring with Robin, he always held back a bit—subconsciously hesitant.
So, when Raqi was chosen to join the Combat Maid Corps, Rosinante decided: whenever possible, let Robin and Raqi train together. Through duels, they could identify and work on each other's weaknesses—training in a more targeted and effective way.
As for the Speed-Calculation Fruit retrieved from Marine HQ, Rosinante handed it directly to Raqi. He also asked Robin to help teach Raqi a wide range of knowledge.
At first, Rosinante had considered giving the fruit to a scientist or an expert in advanced mathematics, hoping they could better utilize its potential.
But the more he thought about it, the more he rejected that idea.
In the world of One Piece, Devil Fruits had a unique rule: to truly bring out their full power, physical strength was just as essential as creative use.
Sure, a genius scientist or mathematician might tap into the Speed-Calculation Fruit's utility—but they'd never unlock its full potential. Most scholars, scientists, or number crunchers were frail, untrained, ordinary people. Without battle-hardened bodies, how could they wield the destructive might of a Devil Fruit?
So Rosinante made his decision: he would raise his own researcher from scratch.
If Robin hadn't already eaten the Flower-Flower Fruit, she would've been the perfect candidate. But since a person couldn't consume two fruits, she was no longer eligible.
And that's how Raqi was chosen to inherit the Speed-Calculation Fruit.
She was a warrior of the Shandia tribe—physically strong and resilient. With proper training, she could unleash the full power of the fruit.
More importantly, Raqi was one of the few Shandians who possessed both gentleness and patience. These qualities made her ideal for mastering the fruit's intellectual abilities.
So Rosinante entrusted her with the fruit and paired her with Robin—for mutual growth.
Robin would teach Raqi knowledge and theory, while Raqi would train Robin in combat. The two little girls ended up becoming perfect complements for each other.
Just then, Bins came hurrying over, his face visibly tense.
Robin and Raqi instantly stopped training, puzzled by Bins's expression. They knew something must be wrong—Bins rarely lost his composure like this.
Rosinante also lifted his head, eyes narrowing.
"Your Majesty, something's wrong. Look—it's the first mate's life paper!" Bins held out a small piece of burning paper.
Rosinante took a glance. The life paper was already halfway burned—but after a moment, it began to slowly recover, only to ignite again soon after.
A life paper represented the vitality of a person. When someone was grievously wounded or near death, their life force would fade—and the paper would burn, turning to ash.
The strange flickering—burning, then recovering—meant only one thing: Katakuri had suffered critical injuries, but some powerful healing or stasis technique was temporarily holding the damage at bay.
"It seems… Katakuri's in real danger," Rosinante murmured, his voice calm but laced with concern.
One look at the life paper, and he could tell things were bad.
"From the looks of it… he's already clashed with that old hag," Bins added grimly.
Ever since Rosinante had asked Bins to keep an eye on Katakuri, he had taken that responsibility very seriously.
Of course, he couldn't monitor Katakuri directly all the time. After Katakuri had left, Bins had lost track of him—mainly due to a lack of wormhole coordinates in the New World. Finding him without those made it nearly impossible.
So instead, Bins stationed someone to monitor Katakuri's life paper around the clock.
Just moments ago, that person rushed in, reporting an alarming change in the paper's condition.
Bins checked it for himself—and immediately came running to Rosinante with it in hand.
"Heh, our first mate really has it rough. Imagine having that woman for a mother," Rosinante chuckled dryly. "I'm not much luckier myself. Just dealt with the Marines—and now I have to deal with one of the Emperors of the Sea."
"But our pirate crew's only just begun—we can't afford to lose someone like Katakuri."
"Bins, do we have any wormhole coordinates in the New World?"
"There aren't any in the Blue Sea section of the New World," Bins said, "but I do have one in a Sky Island located directly above Totto Land's waters."
Wormhole coordinates weren't something Bins could just place anywhere at will. Creating one consumed his ability's energy. Otherwise, he would've long covered the entire world in wormholes.
"Then send me there," Rosinante said.
"Understood," Bins replied.
"Rosinante-nii, be careful!" Robin said just then, running up and handing him his sword.
"Don't worry," Rosinante said with a smile, accepting the blade and strapping it to his waist. "Even if it's Charlotte Linlin we're dealing with—I'm not afraid of her."
Bins had already opened the wormhole portal.
"Your Majesty, this is one of my emergency teleportation stones. If things get out of hand, just crush it. I'll open the wormhole and bring you back immediately," Bins said, handing Rosinante a small stone.
"Got it." Rosinante patted him on the shoulder, tousled Robin's hair fondly, and then stepped into the swirling wormhole.
Half an hour earlier…
"Elbaf Spear: Ikoku Sovereignty!" Charlotte Linlin roared, slashing down with her immense blade.
It was the Giant Tribe's ultimate secret technique—an earth-shattering slash so powerful, it resembled a divine spear crashing down from the heavens.
The moment the attack was unleashed, Katakuri instinctively tried to dodge—but he was a step too late.
The devastating slash tore through the air like an unstoppable lance, and in a split second, half of Katakuri's body was obliterated.
Not just that—everything in front of and behind him was reduced to rubble under the terrifying arc of the slash.
The grand gates of Cake Castle? Blown to bits.
The sheer force of Ikoku Sovereignty had carved a gaping hole clean through the heart of the Big Mom Pirates' stronghold.