The New World.
Marine Base G-5.
Beep. Beep. Beep.
The shrill scream of a red alert, the highest security level, tore through the base. Explosions erupted across the compound in rapid succession.
"Damn it. All units, prepare yourselves. Fire!"
Boom. Boom. Boom.
Dozens, then hundreds of shells rained down on a single location, triggering a chain of violent detonations.
"Did we get him?"
A marine asked with desperate hope.
"No. Not yet."
Another marine stared in horror at the silhouette emerging from the smoke and fire.
"Sea-Prism Stone Unit, deploy!"
At the command of a rear admiral, dozens of Sea-Prism Stone nets shot through the air, cascading down over the towering, demon-like figure.
"Haha, we got him!"
"That's it. He's a Devil Fruit user. Once he's restrained by Sea-Prism Stone, he has nowhere to run!"
"We did it. We caught the monster!"
Cheers erupted across the battlefield.
Then, in the very next second, every voice died.
The smiles vanished from the marines' faces, replaced by absolute despair.
"He… he tore through the Sea-Prism Stone nets. Is this really what they call the strongest creature on land, sea, and sky?"
The vice admiral commanding the base whispered in terror.
Crack.
Thunder split the heavens as blinding lightning connected sky and earth.
"Wororororo!"
A massive azure dragon surged into the air. Its jaws opened, unleashing searing dragon breath that erased everything in its path.
"Hic. Still can't die today, huh?"
The dragon muttered lazily.
"But the Navy's booze wasn't bad. Hic. So… where to next? Right. There's supposed to be an island surrounded by endless storms…"
…
…
The New World.
Tenrou Island.
An isolated island locked within perpetual tempests.
Endless wind and rain formed a natural barrier around it, preventing any ship from approaching.
Yet at the island's heart, like the eye of a storm, the land remained eternally calm.
At this moment, in the southwestern forest.
Whoosh.
Blazing flames surged like rivers of light.
"Fire Dragon's Iron Fist!"
Rosha, dressed in rough, primitive garb, launched himself into the air. Flames roared around his clenched fist.
"Awooo!"
A massive white wolf over ten meters long howled, pushing off the ground and lunging toward him with jaws wide open.
Bang.
Boom.
Rosha's fire-wreathed punch slammed directly into the wolf's face.
An overwhelming force erupted outward. The wolf's enormous body was sent flying, smashing through more than a dozen towering trees before crashing into the ground, motionless.
The forest ignited under the impact.
Before the flames could spread, Rosha inhaled sharply. The fire from all directions twisted unnaturally toward him and vanished into his mouth, completely devoured.
"Once I eat it, the power just keeps flowing."
He exhaled slowly.
"Looks like I can keep going."
His gaze shifted toward the colossal creatures watching from a distance, selecting his next opponent.
A ten-meter-tall silverback gorilla.
A serpent stretching over a hundred meters.
A mammoth.
Even an ancient long-necked dinosaur.
Every one of them trembled.
They were the native rulers of this island, each dominating its own territory. That balance had held until ten years ago.
Ten years ago, this isolated land received an unexpected visitor.
Rosha.
A man from another world.
One moment, he was crossing the street. The next, a speeding truck sent him straight into a completely different reality.
When he first woke up on this monster-infested island, Rosha had been terrified.
Fortunately, his starting point was a safe zone. The beasts never approached the giant tree at the island's center.
Beneath that tree, he discovered a treasure chest.
Inside was his beginner's gift.
Fire Dragon Slayer Magic.
Rosha knew this power well. It was the signature magic of the protagonist from Fairy Tail.
Dragon Slayer Magic was a lost ancient art, a power created to battle dragons themselves.
Fire Dragon Slayer Magic allowed the user to command devastating, ultra-high-temperature flames at will.
More than that, Dragon Slayers transformed their bodies into something closer to a dragon's, granting immense physical strength and endurance far beyond ordinary humans.
They could also restore their stamina and magic by consuming fire, giving them near-limitless combat endurance.
It was magic, elemental control, and raw physical power all in one.
The massive tree covering the island, the Fire Dragon Slayer Magic.
Rosha was almost certain he had arrived in the world of Fairy Tail.
That suspicion was soon confirmed when he discovered a stone monument bearing two weathered characters.
Tenrou.
Excited at first, Rosha imagined joining Fairy Tail, fighting alongside Lucy, Erza, Mirajane, Wendy, Natsu, Gray.
Then reality hit.
He was trapped.
The storms around the island never ceased. Even with a ship, escape would be impossible.
Worse still, this world had Acnologia, the Black Dragon King. A monster who slaughtered dragons and Dragon Slayers alike.
To Acnologia, Rosha would count as a dragon.
If they ever met, even if Rosha perfected his magic, death would be instant.
Rosha had no illusions about that.
After all, even God Serena, bearer of the power of eight dragons, had been killed effortlessly.
So Rosha chose caution.
He stayed on Tenrou Island, training relentlessly while waiting for the Fairy Tail guild to arrive.
Ten years passed.
Over that decade, Rosha honed his Fire Dragon Slayer Magic to its absolute peak.
The island's apex beasts had all been beaten into submission, reduced to sparring partners.
"Day three thousand six hundred fifty-three without Fairy Tail."
Rosha withdrew his gaze from the sea and prepared for another battle.
Then the island shook.
Boom.
The ground trembled violently.
Rosha spun around as a massive cloud of dust rose from the forest several kilometers away.
Minutes later, he arrived at the scene.
A crater a hundred meters wide lay before him.
Sand and debris churned thickly through the air. Rosha did not rush forward. His heightened Dragon Slayer senses detected an overwhelming beastly presence within.
He waited.
If it was Acnologia, he would turn around and run without hesitation.
Crash.
Something moved.
The dust was torn apart as the figure revealed itself.
The moment Rosha saw it, his eyes widened. His mouth fell open. His mind went blank.
After ten years of waiting, he had not met Fairy Tail.
He had met a dragon.
Not the Black Dragon King.
But Kaido.
An azure dragon.
This was not the world of Fairy Tail.
This was the world of One Piece.
"What the hell?"
Rosha shouted.
"I was already preparing for the Fairy Tail S-Class Trial, and now you're telling me this is One Piece?"
…