To all my adoptive fathers: please leave a comment after reading. If you have any suggestions or spot anything I got wrong, feel free to point it out in the chapter comments. I'll read them all carefully.
East Blue, Goa Kingdom, Mt. Colubo.
"Rumble!"
A pale bolt of lightning ripped through the pitch-black night. Torrential rain crashed into the dense primeval forest as if the heavens had opened.
In weather so awful the sheets of rain blurred everything from view, a wild chase was unfolding deep in Mt. Colubo.
A mutated saber-toothed tiger, over five meters long and covered in hard scales, raced through the mud in terror. It was the undisputed ruler of this forest, but now its cold, vertical pupils held nothing but despair.
It was running for its life.
"Hahaha! Don't run, kitty! Weren't you just trying to eat me?!"
A clear, wildly exuberant laugh rang out from above the treetops over the tiger's head.
"Bam!"
A thick tree trunk snapped beneath a burst of tremendous force. A black-haired boy who looked about ten, bare-chested, plunged from above like a meteor and landed right in front of the tiger.
His black hair curled slightly, and a few freckles dotted his cheeks. Though only ten, his muscles were taut as a leopard's. The icy rain beat against his body, raising wisps of hot steam.
In his hand, he gripped a heavy, broad-bladed iron sword in reverse. Its blade was chipped all over and had never been sharpened.
He didn't assume a swordsman's stance or use any fancy techniques.
The boy simply grinned with excitement. The next moment, he drove off with both legs, blasting a deep crater into the mud, and shot toward the enormous beast like a cannonball.
"Get down!"
Gripping the hilt in both hands, he wielded the heavy iron sword like a plain club and brought it crashing down on the saber-toothed tiger's head!
The air split with a shrill sonic boom. The muscles in the boy's arms swelled in an instant, veins bulging beneath his skin like coiling dragons. He unleashed every ounce of the monstrous strength packed into his ten-year-old body!
"Crack!"
With a bone-chilling snap, the saber-toothed tiger's massive body was smashed to the ground by his unreasonable brute force. Its skull sank deep into the mud. It twitched twice, then fell still.
"Phew, that thing sure had thick skin."
The boy casually rested the iron sword on his shoulder and gulped down rainwater tinged with blood. Then he burst into hearty laughter. "At least I've got something extra for dinner tonight!"
"You brat, you've gotten even stronger!"
A voice like rolling thunder rang out through the downpour.
A burly old man in a floral shirt had appeared ten paces away without a sound. He looked at the dead beast, shock and complicated emotions flickering in his shadowed eyes.
"Oh? You're back early this time, old man Garp."
The boy named Ace didn't turn around. He casually shook the blood from his sword and grinned. "I heard your footsteps—and that terrifying presence of yours—from a kilometer away."
Garp's eye twitched.
He heard him?
In a thunderstorm, deep in the mountains, he could hear someone's heartbeat and sense their presence from a kilometer away?
Observation Haki! And not just any kind. He had it from birth, without even needing to train—an innate Observation Haki of the highest order, akin to the Voice of All Things!
"What a monster... Born to break every rule."
Garp muttered inwardly. He strode forward, raised his massive fist, and coated it in black Haki before bringing it down hard on Ace's head!
"Take this! Fist of Love!"
Faced with a fist capable of smashing mountains, ten-year-old Ace didn't dodge like an ordinary child. Instead, he raised his unsharpened iron sword and met Garp's punch head-on!
"Boom!!"
A visible shockwave burst between the grandfather and grandson, instantly sweeping away the rain around them.
"Crack!"
The iron sword shattered. Ace flew back like a broken kite, crashing through three trees before finally coming to a stop.
"Ow, ow, ow! You old geezer, you still hit way too hard!"
A blow that would have pulverized anyone else barely fazed Ace. He climbed out of the wreckage and brushed off the dirt. The terrible bruise on his chest was already fading before their eyes.
Garp watched him, utterly speechless.
Roger's son, whom he had taken in as a baby, had displayed terrifying talent from the moment he was born.
By the age of three, he was already fighting beasts in the forest, seemingly incapable of exhaustion. He had a bottomless supply of energy—more than even Roger had ever possessed.
"Brat, take your catch and get back to Dadan!" Garp grunted. He turned and strode into the rain, helplessness lingering in his retreating figure.
Roger, what kind of monster did you leave behind?
The rain kept falling.
Ace glanced at the hilt and the half of the blade left in his hand, then casually tossed it into the mud. With one hand, he dragged the heavy saber-toothed tiger's body.
Beneath the flickering light of the lightning, he looked down at his youthful, freckled face reflected in a puddle.
"Portgas D. Ace... Heh."
Ace murmured to himself, a defiant curve lifting his lips.
Garp had no idea what kind of mature, ambitious soul was hidden inside the body of this ten-year-old boy.
He wasn't the original Fire Fist Ace, who had been insecure, desperately craved affection, and ultimately died in the Paramount War over a ridiculous taunt.
He was a transmigrator.
More precisely, his soul had fused with this body on the deepest level while he was still in the womb.
This reshaping of his soul across dimensions had given him three trump cards powerful enough to overturn the world.
First, he had innate Observation Haki and the Voice of All Things. He had been able to hear the world ever since he became conscious.
Second, he had the energy of a monster. He wasn't as absurdly durable as Big Mom's Iron Balloon, but it was more than enough to help him handle Garp's hellish training perfectly. He was so full of energy that he barely needed to sleep. When everyone else was exhausted, all he needed was to sit and catch his breath before he could get back on his feet.
And then there was the most terrifying third point...
Ace slowly raised both hands, sensing the "two abysses" within him, born from his soul's doubled strength.
In this world, everyone could eat only one Devil Fruit. Eating a second one made them explode.
But he was different.
His soul had the capacity from birth to bear the arrival of two devils!
"Second Division Commander of the Whitebeard Pirates, or the tragedy of being pierced through the chest by Akainu..."
Dragging his prey through the storm, Ace laughed aloud among the trees. There was not the slightest fear of fate in his laughter—only defiance, as if he would trample every rule beneath his feet.
"Since the heavens gave me another life, and sent me into the Great Pirate Era with a trump card I was born with,"
"I'm not going to be the son of one of the Four Emperors!"
"Gods or Celestial Dragons, it doesn't matter. I'll take this world with my own two hands!"
Before you continue