Cement and Steel — Chapter 4: The Fortress of Trials
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The sun was just beginning to rise as the Thousand Sunny approached a small, rocky island shrouded in mist. The island's jagged cliffs rose sharply from the sea, crowned by the ruins of an ancient fortress.
"We're here," Nami announced, her finger tracing the map. "This is Grimrock Island — said to be a testing ground for pirates brave enough to seek treasure and glory. Legend says the fortress holds secrets from the Void Century."
Kaito tightened the straps on his cement-armored gauntlets. "A test, then. I like that."
Luffy's eyes gleamed with excitement. "Treasure and adventure? Count me in!"
The crew dropped anchor in a sheltered cove, and soon they were disembarking, eager to explore.
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The fortress loomed above them, massive walls cracked and overgrown with vines. Kaito's footsteps echoed on the stone as he led the way inside, his cement feet steady against the crumbling floor.
"Stay alert," Zoro warned. "This place looks like it's been waiting for us — traps, enemies, who knows what."
As they ventured deeper, strange symbols etched into the walls glowed faintly, pulsing with an ancient energy.
Kaito's Observation Haki tingled sharply. "There's something here… something powerful."
Suddenly, the floor beneath them rumbled. Stones shifted and giant pillars slammed down, blocking their path.
"We've triggered a trap!" Usopp shouted, dodging as a stone pillar swung toward him.
Kaito reacted instantly, raising a wall of hardened cement to shield Usopp. The pillar crashed against it, splintering but holding firm.
"Good timing," Luffy laughed, stretching his arm to punch a swinging pillar away.
The crew fought their way through a gauntlet of traps — spike pits, falling stones, and swinging blades — but the fortress seemed to challenge more than just their physical strength.
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In the heart of the fortress, a massive stone door barred their way. Inscribed in ancient script was a riddle:
*"Only those who blend strength with wisdom shall pass."*
Nami studied the inscription. "Strength with wisdom… What could that mean?"
Kaito stepped forward, examining the door closely. "In my world, cement is not just strong — it's crafted carefully, mixed with knowledge of minerals and timing. Perhaps the answer lies in how we use our power."
He extended his hands, molding a sample of cement carefully on the ground, shaping it not as a solid block but as an interlocking structure — strong yet flexible.
Suddenly, the door trembled and slowly slid open.
"Looks like you cracked the code," Zoro grunted approvingly.
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Beyond the door lay a vast chamber filled with stone statues — warriors frozen in time, each holding weapons carved from unknown materials.
One statue's eyes suddenly glowed red.
"Trap!" Usopp yelled.
The statue lunged forward, its stone sword swinging down toward the crew.
Kaito stepped in front, raising a shield of cement to block the blow. The impact shook him, but the shield held.
Drawing on his Armament Haki, Kaito reinforced the cement, hardening it to an almost indestructible level.
He countered with a massive hammer strike, shattering the statue's weapon and cracking its stone form.
More statues awakened, surrounding them.
The battle was fierce. Kaito's cement powers allowed him to absorb and redirect blows, create barriers to protect his friends, and launch powerful attacks shaped like massive stone fists or spears.
Luffy and Zoro fought side by side, their strikes swift and precise. Sanji's kicks flowed like fire, breaking the statues' limbs.
Usopp's sharpshooting kept the statues off balance, while Nami manipulated weather to create gusts of wind and lightning.
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Mid-fight, Kaito's body began to tremble under the strain. The cement coating felt heavier, almost like it was drying too fast and cracking.
*I need to control the curing better,* he thought urgently.
Drawing on his knowledge, Kaito slowed the cement's hardening process around his joints, making it more flexible without losing strength. His Haki flared again, sealing the surface with invisible energy to prevent cracks.
With renewed strength, Kaito leapt high and formed a spear of cement from his arm, piercing through the central statue's chest.
The stone warriors crumbled to dust.
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Breathing heavily, the crew gathered in the chamber's center.
Nami examined a carved pedestal, where a glowing orb rested.
"This must be the treasure," she said softly.
Kaito reached out and touched the orb. A sudden rush of knowledge flooded his mind — visions of ancient battles, forgotten history, and powerful techniques.
He gasped, staggering.
"Are you okay?" Luffy asked.
Kaito nodded slowly, awe in his eyes. "This… this is a key to lost Haki techniques and advanced cement mastery. With this, I can push my powers further."
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Back on the ship, Kaito spent hours practicing. Using the orb's knowledge, he learned to blend his cement powers and Haki in new ways.
He could now create flexible cement limbs that shifted like living stone, form reinforced armor that adapted during battle, and even manipulate the density of his cement to control weight and impact.
As night fell, Kaito stood at the bow, gazing at the stars.
He had come to this world a stranger, a man out of place. But now, with the strength of cement and the bonds of his new crew, he was becoming something greater.
A guardian, a warrior, and perhaps one day — a legend.