On the secluded outskirts of the Goa Kingdom, within a hidden, salt-aired shipyard.
Thud.
A heavy leather suitcase was slammed onto a workbench cluttered with blueprints and cedar shavings. The latches clicked open, revealing a staggering hoard of eighty million Berries. The sheer volume of cash cast a golden, intoxicating luster against the dim walls of the workshop.
Thirteen-year-old Sabo adjusted the brim of his top hat, his expression calm as he faced the retired Master Shipwright. The old man stood frozen, his pipe trembling between his fingers.
"Eighty... eighty million?" The shipwright swallowed hard, his eyes darting from the money to the boy. "Kid, that's enough to build a galleon that would make a Marine Vice Admiral jealous. What kind of monster are you trying to put on the water?"
"We don't need size," Sabo said, sliding a hand-drawn blueprint across the table. His voice was steady, professional. "The ship only needs to be a medium-sized schooner—room for a dozen or so. But our Captain has three non-negotiable demands."
He tapped the paper. "First: The keel and frame must be forged from the finest timber in the East Blue. We want absolute structural integrity. It must be able to laugh at the currents of the Grand Line."
"Second: Speed. The hull must be streamlined to the limit. I want the fastest ship on this blue earth."
"Third: Comfort. The galley, the sleeping quarters, the training deck—everything must be luxurious. We are going to sea to conquer, not to suffer."
The Master Shipwright took a long, sharp breath. Using a warship's budget on a small schooner meant every plank could be hand-polished, every joint reinforced with surgical precision.
"A dream order," the old man whispered, his eyes turning fervent as he touched the blueprint. "No cost spared... it's a shipwright's fantasy. But to do this right, to select the wood and cure it... it will take three years."
"That's perfect," Sabo said, closing the suitcase. "We'll be back for her in three years."
Time slipped through their fingers like fine sand. Winters bled into summers, and the leaves of Mt. Colubo withered and bloomed twice more.
Two years later.
Deep within the primeval heart of the mountain, a dull, bone-crunching thud shattered the morning stillness.
BOOM!
A mutated Great Crocodile—a beast the size of a small house—was caught mid-lunge by a lightning-fast side kick. Its massive jaw cracked as its entire body was flipped in mid-air, slamming into the mud where it lay instantly unconscious.
Sunlight filtered through the canopy, illuminating the young man who stood with his leg retracted.
At fifteen, Ace had reached a staggering 2.2 meters in height. The boyishness was gone, replaced by a physique that was a masterpiece of martial evolution. His shoulders were broad, his muscles defined with the precision of a sculptor's chisel. It wasn't the bulky mass of a weightlifter, but the high-density, corded power of a predator.
His temperament had shifted. He was no longer a flamboyant spark; he was a cold, introverted pressure. Even standing still, he exuded the aura of a top-tier hunter.
"Ace's kicks are getting scarier every day," Luffy muttered from a nearby branch, biting into an apple.
Suddenly, Ace's eyes shifted. His Observation Haki, sharpened by years of forest survival, caught a familiar, crushing presence approaching at terminal velocity.
"You brats! I leave for six months and I find you bullying the local wildlife again?!"
With a localized gale, Garp landed atop a massive boulder twenty meters away. His Marine "Justice" coat fluttered in the wind as he cracked his knuckles, the sound like small trees snapping.
"Grandpa!" Luffy yelped, nearly tumbling from his perch.
Ace said nothing. He slowly turned, reaching out to drive his heavy machete deep into the mud to clear his hands. As Garp lunged from the rock, hurtling toward him with a boulder-sized fist raised high, Ace's focus narrowed to a razor's edge.
"Let's see if you've been slacking! Iron Fist of Love!"
Garp blurred, appearing before Ace as if he had folded space. Pitch-black Armament Haki surged over his fist, creating a sonic boom as he swung downward with zero restraint.
In years past, Ace would have met this with raw, desperate strength and been sent flying into the next forest.
But today...
Ace's feet sank into the earth, stamping two deep craters into the mud. He didn't retreat. He didn't reach for his blade. He coiled his right arm, tensing every fiber of his being.
For five years, I've watched you. I've felt how you move. I've memorized the flow of your spirit.
Ace lunged forward, meeting the Vice Admiral's fist with a punch of his own. As his arm swung, he mobilized the blood and will he had tempered since childhood.
Hum—!
Garp's eyes widened in genuine shock. He saw it clearly—on Ace's bronze forearm, a layer of iron-black luster had manifested. It was faint, but it was undeniable.
Busoshoku: Koka!
BOOM—!!!
The collision of two black-clad fists unleashed a shockwave that tore the earth apart. Grass and shrubs within thirty meters were uprooted instantly. The pressure wave was so intense that Luffy had to shield his eyes from the flying debris.
Crack!
The ground beneath Ace's feet splintered. Even with Haki, the sheer gap in experience and power forced him back. He plowed two deep furrows into the mud as he skidded seven meters, but he didn't fall.
He stood his ground.
The dust settled. The silence that followed was deafening.
Ace slowly retracted his arm, the black hardening fading back into bronze skin. He looked at Garp, his breathing steady, his expression one of calm inevitability.
Garp stared at his own fist, then at the teenager before him. For the first time in his life, the legendary Marine felt a chill of disbelief. He had never taught Ace a single mantra for Haki. Not one.
This boy... by sheer observation, muscle memory, and getting beaten for five years... had deduced the secret of Armament Haki on his own the moment his body was ready to bear the load.
"Old man," Ace broke the silence, his tone devoid of boastfulness. "My 'wild' method is inefficient. It burns through my stamina too fast."
He looked Garp in the eye, his voice firm. "My foundation is set. My body can take it. Now... teach me the advanced applications. Systematically."
Garp was stunned, his shock slowly melting into a complex, prideful grin. He tore off his Marine coat and tossed it aside, his bones popping with a sound like gunfire. A terrifying, true aura of a legend erupted from him.
"Fine, brat. Since you kicked the door down yourself..." Garp's grin turned feral. "Prepare yourself. I'm going to hammer the essence of Haki into your marrow!"
Ace nodded. A sharp, lethal glint flickered in his eyes.
Two years remained. The transformation into a monster had officially begun.