Year 1510, Sea Circle Calendar.Impel Down — Level One: Crimson Hell.
The voice came first.Harsh. Sneering. Stripping away the fragile comfort of unconsciousness.
"Oi! Wake up, maggot. Food time. Or is it your last meal, huh?"
Then came the pain. A heavy boot smashed into Shun Kaien's ribs, driving the breath from his lungs. The agony cut through the haze of sleep, dragging him into a world of suffocating heat and choking darkness.
Shun coughed, curling instinctively, clutching his side. His body felt weak, brittle, as though he'd been drained dry.
Through blurred vision, he caught sight of the man looming over him.A Marine.White coat. Green slacks. Standard issue. But there was nothing standard in his expression.It was the look of someone who'd long since stopped seeing prisoners as people.
"Impel Down. Crimson Hell. You're in the first level now, pirate scum."The Marine crouched, grinning like a shark."Not many make it past this floor. Might as well enjoy your slop while you can."
With a bark of laughter, the man turned and stomped out, the door slamming shut behind him like the toll of an execution bell.
Alone again, Shun pushed himself upright, his breathing ragged, his vision swimming.
Where the hell... am I?
The question echoed in his skull.
But the answer came not from his own memories, but from a deluge of foreign ones that crashed over him without mercy.Images, names, histories—flooding into him like a broken dam.
He groaned, clutching his head as the memories clawed their way into place.
When the storm passed, he slumped against the cold, filthy wall, shivering despite the humid heat.
"...This is the world of One Piece."
The name tasted alien on his tongue, but the certainty in his gut was absolute.
Somehow, impossibly, he'd transmigrated into this universe.But no, it wasn't some heroic saga where he got to be a pirate king or a legendary swordsman.He wasn't even some young talent on a promising ship.
He was a nobody.Just another cannon-fodder pirate.Captured. Disarmed. Imprisoned.
And the worst part?They hadn't even given him a Devil Fruit or some cheat-like weapon.Just his aching, mortal body.
He laughed hollowly, leaning back against the stone.
This is bad.This is worse than bad.Impel Down. The worst prison in the world.
He remembered it now, the stories, the fear that rippled even through the strongest crews.
Buried deep beneath the sea.Guarded by monstrous beasts and sadistic jailers.A fortress no one escaped from—except one man, decades ago.
Shun clenched his fists, nails digging into his palms.This wasn't a dream. This was death creeping ever closer.
But just as the despair threatened to swallow him whole—
System Notification:[Naruto Character Possession Protocol] successfully established.Introductory Sync Pack available. Access Inventory to claim your first Synchronization Item.
Shun froze.
The voice was cold. Mechanical. Unmistakable.
He exhaled slowly, almost afraid to believe it. But the interface shimmered into existence inside his mind with a thought.
Host: Shun KaienSynchronized Characters: NonePossession Tokens Remaining: 0Reputation Points: 0
His eyes narrowed, absorbing the clean, almost sterile display.No ornate flair.No unnecessary fanfare.
Just data.
"Naruto... Possession Protocol?"
He recalled it now. Another world. One of shinobi. Chakra. Jutsu.
Was this his key?His edge?
He pushed the question aside for now and focused.The Introductory Sync Pack floated on the screen.He claimed it without hesitation.
System Notification:[Introductory Sync Pack opened.]You have obtained: Might Guy (Synchronization Template)Possession Tokens: +10 (Each grants 1 hour of synchronization.)
His pulse quickened.
Might Guy.The Blue Beast of Konoha.The man who opened the Eight Gates and stood face to face with Uchiha Madara himself.
Shun swallowed hard, watching as the interface updated.
Host: Shun KaienSynchronized Characters: Might Guy (Template)Possession Tokens Remaining: 10Reputation Points: 0
It was simple.For one hour, he could synchronize with Might Guy, gaining his physical abilities, his techniques, his power.
But once that hour was gone, he'd be back to being Shun Kaien.A pirate. A prisoner. A nobody.
His gaze shifted to the System Shop, where the cold math of the universe stared back at him.
Sage of Six Paths (Sync Template): 10,000,000 Reputation Points.Madara Uchiha (Sync Template): 800,000 Reputation Points.Possession Token (1 hour): 1,000 Reputation Points.
And him?Zero points.Zero leverage.
At the bottom, a line of text blinked patiently:
[Reputation Points are gained by defeating strong opponents. The stronger the opponent, the greater the points earned.]
Shun allowed himself a small, bitter smile.
In the end, the world was simple.Fight. Kill. Survive.The only difference now was that his prey would feed both his freedom—and his system.
No shortcuts.No miracles.Just a single edge.Might Guy's power—and ten hours to use it.
Shun closed his eyes, steadying his breathing.
He didn't need to be the hero of some grand tale.He just needed to live.
And if blood was the only currency this world respected,he was ready to pay.