The Queen's Grace sailed toward the distant silhouette of Kurogane Island, also known as the Island of Black Iron. The winds were steady, but the tension among the crew was building. This island was unlike the others they'd visited. There were no grand cities, no bustling ports. Only smoke rising from the forges and rumors of ancient weapon smiths hidden deep within its forests.
According to Nojiko's intel, Kurogane Island was a neutral ground—neither controlled by the World Government nor pirates. It was a place where old swordsmith clans still existed, where weapon masters forged blades that could rival even the Supreme Grade swords.
Kaito stood at the ship's bow, arms crossed. "They say there's a hidden forge here… one that produces materials strong enough to handle thunder-infused weapons."
Kuina, who was now in the middle of refining her Thunder Blade, glanced over. "Do you think the swordsmiths here will accept outsiders?"
Khalifa, flipping through the latest Marine reports, answered with her usual calm. "That depends on how we enter the island. The swordsmiths here respect strength, not authority."
Carmen cracked her knuckles. "If it's strength they want, we can show them plenty."
Nojiko smiled faintly. "Just don't burn down the forge, Carmen."
The ship glided into the mist-covered harbor, the entrance eerily quiet. No Marine flags. No pirates loitering. Just an oppressive silence and the faint clang of hammers on steel echoing from the mountains.
Arrival at Kurogane Island
The moment they set foot on the black-sand shore, they were greeted by a cloaked figure—a blade apprentice who said nothing, only gestured for them to follow.
The crew exchanged glances but complied.
As they traversed winding forest paths, the clang of swords being hammered grew louder, resonating through the trees like a heartbeat. The apprentice led them to a hidden village where forges burned day and night, illuminating the shadows of the craftsmen who had long isolated themselves from the world.
An elder swordsmith finally stepped forward, his face worn, his gaze sharp.
"You come here seeking something," he said.
Kuina stepped forward without hesitation. "I want to perfect my blade—to forge one that can withstand the power of thunder without breaking."
The elder's eyes gleamed with faint amusement. "The power of gods is not so easily wielded. Even the greatest of swords can shatter when burdened by such force."
"I'm prepared for that risk," Kuina replied, her voice steady.
The elder's gaze swept over the rest of the crew before settling on Kaito. "And you, captain? What is it you seek here?"
Kaito smiled. "Nothing special. Just the chance to see how far we can push our blades. We're not looking for world conquest or titles."
The elder raised an eyebrow. "Not even Pirate King?"
"No," Kaito said simply. "We just want to live our story on the sea."
The swordsmith's expression softened, and after a long silence, he finally nodded. "Then you may stay. But you will not simply purchase a blade here. You will earn it."
Training Begins: Kuina's Blade Tempering
The days that followed were grueling.
Kuina was not handed a completed sword. Instead, she was tasked with assisting in the forging process under the elder's watchful eye. She hammered, folded, and reheated the metal herself, pouring her understanding of thunder into every step.
Each night, she would collapse by the fire, exhausted but exhilarated.
Yamato sparred with her between forging sessions, keeping her combat senses sharp. Carmen cooked hearty meals to refuel their bodies, while Aisa and Conis helped carry supplies and gathered rare ores from the forest.
Khalifa took the opportunity to infiltrate the hidden libraries beneath the village, uncovering blueprints of ancient Wano forging techniques long thought lost.
Nojiko handled negotiations with the forge elders, ensuring the crew remained welcome despite their growing bounties.
Kaito observed, occasionally stepping in to spar with Kuina when her energy burned too fiercely to be contained.
Meanwhile: Straw Hat Movements
Farther south on Wano's coast, the Straw Hat crew continued their progress.
Zoro, having heard the rumors of the Black Iron Island, felt a pull he could not explain.
"Kuina's there," he said, eyes sharp. "Her blade is evolving. I need to go."
Luffy, chewing on a piece of meat, grinned. "Let's go then! Sounds fun!"
Nami sighed, "Do we really need to get involved with Kaito's crew again so soon?"
Sanji lit a cigarette, his expression unusually serious. "Zoro's not the only one with unfinished business. Carmen's been cooking up storms in every kitchen we pass. I can't ignore her."
Robin smiled knowingly. "It seems fate enjoys weaving your paths together."
Usopp trembled. "We're seriously going to follow them again?"
Franky slammed his fist into his palm. "Super! I'll upgrade our ship's defenses just in case!"
Brook laughed, "Perhaps I'll compose a new song about rivals who keep meeting across the seas! Yohohoho!"
Luffy stood and pointed toward the horizon. "We'll meet them again. I can feel it!"
Marine and Cipher Pol Surveillance
Back aboard the Marine observation ship, Rear Admiral Orlan reviewed the latest intelligence.
"Both Kaito's and Luffy's crews are converging toward the Black Iron Island," a Cipher Pol agent reported. "We've also confirmed the forging of a custom Thunder Blade underway."
Orlan tapped the table rhythmically. "So… it's not just about Yamato anymore. They're after superior weapons."
Another officer added, "There are bounty hunters already making their way to Kurogane Island. The underworld sees opportunity."
Orlan smirked. "Let them come. We'll watch from the shadows and sweep up the survivors."
He crossed his arms, his mind already calculating the collision course both crews were now set upon.
The New Blade: Kuina's Stormbreaker
After weeks of relentless forging and tempering, the day of completion arrived.
The elder swordsmith presented Kuina with the newly forged blade: Stormbreaker.
It shimmered with a faint silver sheen, the edge honed to perfection, the core layered with iron and unique ore that resonated with Kuina's thunder energy.
"This blade," the elder said, "will not shatter under the weight of thunder. But its true strength will only awaken in battle."
Kuina held it, feeling the perfect balance in her grip. The thunder within her pulsed in harmony with the weapon.
"It's beautiful," she whispered.
The elder smiled faintly. "Your journey is far from over."
Kaito approached, placing a hand on her shoulder. "Let's test it soon."
Kuina's eyes flashed with determination. "Against Zoro."
Kaito grinned. "Yeah. Against Zoro."
Under the Black Sky
That evening, as the crew gathered around their campfire near the ship, Khalifa shared news she had intercepted from Marine channels.
"The Straw Hats are on their way here."
Carmen smirked. "Sanji's coming? He must have missed me."
Yamato leaned against her kanabo. "So we'll see them again soon?"
Kaito looked toward the dark horizon, the ocean stretching endlessly before them.
"We'll meet them again. This island isn't big enough for both our stories."
He turned to his crew, their faces illuminated by the flickering fire.
"We're not here to win some race. We're here to see what happens when two crews refuse to back down."
Their laughter echoed into the night.
Somewhere across the sea, Luffy's ship surged toward the same island, his grin just as wide, his excitement just as fierce.
The sea, once again, would decide where their stories would collide.