The midday sun poured down over the Marine training camp, bathing the grounds in warmth and vigor. Recruits hustled through their drills, sweat and grit marking their uniforms.
In the center of the plaza, one figure stood out—not due to excellence, but because he lagged behind. Karen's breath came in sharp gasps, his face flushed with effort as he pushed himself through another lap of basic endurance training.
"My body's still too weak..."
Frustration twisted Karen's expression. He clenched his fists, the sting of fatigue biting deep. No matter how hard he trained, his body simply couldn't keep up.
It had been over a decade since Gol D. Roger's execution sparked the Great Pirate Era. Karen had arrived in this world several years ago, after an untimely accident ended his previous life. Reborn in the world of One Piece, he had dreamed of rising above the waves, a man feared and respected like Whitebeard or Garp. But the dream was fading fast.
In this world where might makes right, Karen's body was subpar—worse even than the average recruit. Despite countless hours of training, he consistently placed at the bottom. No devil fruit, no special bloodline, no secret technique.
"Devil Fruits…" he muttered between pants. "Even the weakest Zoan-type costs millions of berries. Way out of my reach."
He grimaced, shaking his head to clear the hopeless thoughts. If he couldn't become a top recruit here, he'd end up as little more than cannon fodder—especially with the growing tension in the world. The Marines were preparing for future wars, and Karen knew full well that in just a few short years, Marineford itself would become a battlefield during the Summit War.
"No point worrying about that now. Focus on surviving the day."
Karen exhaled deeply and threw himself back into training, forcing his aching limbs to move. He had no friends here. His fellow recruits mocked his weakness, and he had long since stopped trying to fit in.
When training finally ended, he left the grounds quickly, weaving past chatter and laughter that didn't include him. His footsteps led him to a modest home on Marineford—an inheritance left behind when his foster parents, both naval engineers, died during an escort mission in the Calm Belt.
Inside, Karen shut the door behind him and immediately sat cross-legged on his bed. His breath slowed. His mind quieted.
Then, with practiced intent, he closed his eyes—and the world changed.
A mysterious void opened within his consciousness. At its center hovered a glowing tome etched with arcane symbols. It was the Book of Origin, a relic that had appeared in his mind a year ago.
With a focused thought, a translucent status screen materialized above the book, game-like in its clarity:
Book of Origin – Level 1: 100%
(You can now read the Book of Origin.)
When the book first appeared, it had read "Level 1: 0% – Cannot be read." But through continuous training, fights, and meditation, Karen had accumulated progress. And now, finally, it had unlocked.
He inhaled, steadied his thoughts, and reached out mentally to open the book.
Hum...
The space shuddered violently. Power surged. Before him, an enormous crimson dragon materialized, scales gleaming like molten lava. Its roar echoed through the void, a sound that shook Karen's very soul. The beast hovered in the void, eyes locked on him, before slowly dissolving into countless glowing motes.
Karen's thoughts snapped back to the interface:
Book of Origin – Level 2: 0%
(Cannot read until level increased)
Unlocked Ability: Fire Dragon Slayer Magic – Tier 2
His heart pounded.
"Fire Dragon Slayer Magic? Isn't that Natsu's technique from Fairy Tail? A magic said to slay dragons… transform the body… channel fire itself…"
It was a power he'd only known from fiction in his past life. Yet now, it pulsed within him—real, tangible.
He stared in disbelief, then slowly smiled.
"So if I keep leveling up, I'll unlock more of the book… and I can evolve this magic too…"
The possibilities stirred something deep inside him. Excitement. Hope.
Karen withdrew from the mental realm, his senses snapping back to his room. But everything felt different. His body… surged with raw power. His muscles no longer felt weak. Every breath brought heat, and in his mind, he could already picture the fundamental techniques of Dragon Slayer magic—Fire Dragon's Roar, Iron Fist, Flame Wing.
He stood, clenched his fists—and flames licked his knuckles.
"So this is the Dragon's Physique…" he murmured. His blood felt like magma.
And then—he felt something else. A quiet flow beneath the surface. Magic power.
Real magic power.
His eyes widened. This wasn't haki. This wasn't devil fruit power. This was a third path—his path.
Just as he prepared to test the full extent of his new strength, a thought struck him, halting his movement.
Something—no, someone—had appeared near the door. A presence he hadn't sensed before.
He wasn't alone.