A Kaido-Level Constitution and a Mythical Zoan

Deep within the Grand Line, in the New World.

The sea stretched endlessly in every direction. But on a small island somewhere in those waters, a band of pirates was slaughtering and plundering a town with no one strong enough to defend it.

To them, the town was meat laid out on a plate. The lives of its residents mattered far less than whether they would have enough money for drinks that night.

Screams tangled together across the streets. The townspeople had nothing left but despair, and the desperate hope that someone, anyone, would come to save them.

Inside a shabby little house, Caius Redgrave slowly opened his eyes.

Pain tore through him the moment he woke.

"Ah... damn, that hurts."

'What is this? Where am I?'

He had no time to worry about the agony in his body. Caius forced himself upright and staggered to a mirror. His reflection was ghastly pale from blood loss, and the sight drained the last trace of color from his face.

Then a clear chime rang inside his mind.

For an instant, it felt like a drowning man catching hold of a rope.

"S-System?"

[System]

I am here.

Caius realized this was not a dream. He drew in a breath and forced himself to calm down.

The breath tugged at his wounds, hard enough to make him bare his teeth, but the instincts he had carried over from his previous life would not let him waste time.

"System, what can you do?"

[System]

This is the Super Sign-In System.

The host may sign in once per day.

Rewards are random.

Since the host has just crossed into this world and is rapidly losing vital signs, the starter pack has been upgraded by one tier.

Open the starter pack?

"Open it. Hurry."

"If you do not, I am going to die before I even figure out where I am."

Caius felt a grim kind of relief. He was an ordinary man thrown into an unknown world with a bleeding body and no idea what had happened, but at least the system seemed useful.

Without it, he would die today.

The starter pack was his only hope, so he fixed all his attention on what it produced.

[System]

Starter pack opened successfully.

Reward acquired: one full healing treatment.

Note: The host was close to death. Emergency treatment has been included.

Reward acquired: Kaido-level constitution.

Reward acquired: Mythical Zoan-type Fish-Fish Fruit, Model: Red Dragon.

Rewards have been placed in system storage.

Detailed descriptions will be available after treatment.

Excitement surged through Caius when he saw the rewards, only to stall when he reached the last line.

'Is this system terrified I am going to die or something?'

'Not that it is wrong. If this keeps up, I really will.'

"Use the treatment."

[System]

Treatment used.

At once, the pain in his body began to fade. Caius pulled his torn shirt open and looked down.

The wounds were gone. Not even a scar remained.

Once the treatment ended, warmth and strength spread through him. Caius did not waste time celebrating. He opened system storage, switched to the inventory tab, and checked the descriptions of his two rewards.

[System]

Kaido-level constitution: A monstrous body modeled after Kaido, one of the Four Emperors of the sea. After fusion, the host may consider himself as durable as Kaido and survive recklessness that would kill anyone else.

Fish-Fish Fruit, Model: Red Dragon: A system-enhanced Mythical Zoan. Once consumed, it grants command over fire, with its limits determined by the host's development.

Note: A trace of world origin has been fused into the fruit, greatly raising its upper limit.

Caius could not help the excitement that rose in him after reading the descriptions.

The Kaido-level constitution was absurd enough by itself. But the Devil Fruit had been specially enhanced on top of that.

World origin.

That was the foundation that kept a world running, and the system had handed him a trace of it just like that. Even a sliver of something like that had to be absolute top-tier power.

After a few moments, Caius finally forced himself to calm down.

The rewards were incredible, but he still needed to know what kind of world he had landed in. If the people here were monsters, even gifts like these might not be enough.

With that thought clear in his mind, he asked the system another question.

"System, what world am I in?"

[System]

Current world: One Piece.

Current date: Sea Circle Calendar, February 6, 1472.

Caius had already suspected as much from the reward names, but he had not expected the timeline to be this early.

Luffy would not set sail for another forty-eight years.

Still, this era was not far from the founding of the Rocks Pirates. If that happened in 1478, then he had six years.

This was an age he had never had the chance to experience in his previous life. In this life, he would see it for himself and climb to the very top of it.

In the world of One Piece, a fighter's body and Devil Fruit were both vital. A powerful body was the foundation for the three forms of Haki, while stamina determined how long a fighter could remain at full strength. Endurance was what kept power flowing.

Once he had sorted that out, footsteps sounded outside the house.

Caius could not afford to hesitate.

"System, fuse the Kaido-level constitution. Now."

[System]

Reward fusion in progress.

Host, prepare yourself.

Caius did not understand what that meant until pain exploded through his body.

He almost cried out. The danger outside forced him to clamp his teeth together and swallow every sound.

He did not know how long the agony lasted.

When it finally faded, he clenched his fist and felt strength surging through him in a continuous flood.

The change filled him with savage excitement. He tore away the ragged clothes clinging to him and looked down. His once thin frame was now carved with lean, streamlined muscle. Even his height had shot from about five-foot-seven to nearly six-foot-seven.

His strength had increased by more than twenty times.

And that still was not the reward that mattered most.

When the fusion was complete, Caius turned his attention to the Devil Fruit.

Without hesitation, he pulled it from system storage, shoved it into his mouth, and bit down hard.

He had already braced himself for the taste. Instead, he froze.

It was not nearly as bad as he expected.

'Huh. This actually tastes fine?'

Once he realized that, the plan to take only one bite disappeared. Caius quickly ate the remaining flesh of the fruit, and when he finished, he almost wanted seconds.

Fortunately, no one else saw it. If anyone had witnessed a man finish a Devil Fruit and look like he wanted more, their eyes might have fallen out.

'Divine Flame.'

The name appeared in his mind the instant he finished eating.

Caius lifted one finger without hesitation. With a thought, a golden flame bloomed at his fingertip.

The moment it appeared, the shabby house caught fire.

Outside, the pirate captain noticed the flames. He paused, then a cruel look spread across his face as he moved closer.

"Boys, looks like we have a survivor."

"Go on. Kill him."

"Once the person inside is dealt with, we head back to the ship. Tonight, I'll take you to have your fun with some women."

The pirates' eyes lit with crude hunger. They shouted and rushed toward the little house.

Inside, Caius glanced around the burning room and sighed.

It was a wreck, sure.

But for the moment, it was still where he lived.

'Might as well save what I can.'

He lifted one finger.

The flames burning through the room bent toward him as if drawn by an invisible current, then vanished into him.

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