Fire Dragon Slayer Magic—legendary and powerful, yet it came with an unusual flaw: severe motion sickness when riding vehicles. Karen remembered that in his previous world, all Dragon Slayers suffered from it.
But his magic came from the mysterious Book of Origin. Would that drawback still apply?
If it did… then in this sea-faring world of pirates, navies, and endless ocean voyages, that would be a cruel joke.
Determined to find out, Karen decided to test it.
He grabbed his worn-out coin pouch and stepped outside, summoning a hired cart near the Marine barracks.
In Marineford, where land was scarce and every service came at a high cost, even a short ride was expensive. The few thousand berries in Karen's pouch were his total savings—hoarded over months through frugality.
Still, he didn't hesitate. In this world, strength was currency. If he became truly powerful, wealth would follow easily.
Karen gave the coachman a random destination and climbed into the carriage. With a crack of the whip, the cart jolted into motion.
One minute passed. Then two… then five.
Ten full minutes went by. Karen blinked, amazed.
"Nothing... I feel completely fine."
He leaned back in surprise. There was no nausea, no dizziness, no cold sweat—the classic symptoms described in the manga were absent. He even bounced slightly in his seat to test further.
"Incredible. Somehow, I've avoided the motion sickness."
Relieved and excited, he rapped the roof of the carriage and asked the coachman to stop. Moments later, he was sprinting back toward his small home in Marineford, heart pounding—not from exertion, but anticipation.
Back in his courtyard, Karen stood before the wooden training post he'd used for years—scarred from countless punches, but still upright. He clenched his fist, gathering the mysterious power that now pulsed in his body.
With a soft roar, a crimson flame burst forth from his knuckles.
"This is Fire Dragon Slayer Magic…" he whispered, entranced. "Let's see how strong you really are."
He stepped forward and threw a punch.
Boom!
At the moment of impact, the flames erupted like a cannon. The training post cracked with a loud snap, flames consuming it instantly. Within seconds, all that remained was smoldering ash, curling upward in the afternoon breeze.
Karen grinned.
"That's the strength of second-tier Dragon Slayer Magic. Just imagine if I could unlock Dragon King Mode…"
He trailed off, imagining the immense power of the legendary Dragon Force, the transformation known to push Dragon Slayers beyond their limits.
Regaining focus, he continued testing his strength. He punched, kicked, conjured flame, and practiced basic forms. As he moved, he felt it—his body growing stronger, his magic more fluid. Small improvements, but real ones.
Eventually, he stopped, sweating but smiling. His courtyard was scorched, the stone walls blackened with burn marks, debris scattered across the grounds.
Curious, he withdrew into his mental space once more, calling forth the familiar interface:
Book of Origin – Level 2: 1%
(You cannot read the Book of Origin.)
Fire Dragon Slayer Magic – Tier 2
"As I thought, training boosts both my body and the Book's progression."
He stepped back from the mental realm, still musing to himself, when—
Click.
The front door creaked open.
"Karen, are you home?"
A familiar voice drifted into the courtyard.
Karen turned as a young woman stepped through the gate, pausing as her eyes scanned the charred surroundings.
It was Ain.
"Was there… a fire here?" she asked, alarmed. "Are you hurt?"
She rushed forward, inspecting him from head to toe. Only after confirming he was uninjured did she breathe a sigh of relief.
Karen smiled sheepishly. "Haha, don't worry, Ain. I'm fine."
Warmth spread through him at her concern.
Ain was his closest companion—their families had been neighbors in Marineford. Their parents, all Marine officers, had died in separate battles against pirates. Since then, they'd leaned on each other for support.
Though Karen had always looked out for her when they were younger, the tables had turned.
Ain was a prodigy.
She had eaten the Retour-Return Fruit by chance, giving her the ability to revert anything—including people—back to a younger state. Combined with her natural swordsmanship and quick grasp of combat tactics, she had caught the eye of Marine instructors.
It was said that she would soon be transferred to the elite training unit led by the former Admiral Zephyr—one of the most powerful men to ever serve the Navy.
Karen, meanwhile, had been stuck at the bottom. Weak physique. No fruit. No prospects.
Even now, Ain stood out while he remained a footnote in the training logs.
But Ain never changed. Despite rising in the ranks, she still looked after him—checked on him, cheered for him, believed in him.
Because long ago, when both of them were orphaned and she was drowning in grief, it was Karen who had offered her comfort. It was he who told her to keep going, who listened to her tears in the dark, who gave her back her hope.
And now she was doing the same for him.
He looked at her smiling face—concerned, a bit stern, but genuine.
"Thank you," he whispered under his breath.
For not giving up on me.