"Focus more on training your muscles and mastering how to channel strength," Zoro said, flexing his arm and watching the muscles bulge. "After all, with great strength, everything becomes easier."
He raised his arm and clenched his fist, his biceps swelling like a mountain. "There are techniques similar to your Breathing Methods — things like Ichi Gorilla and Ni Gorilla. They can enhance muscle strength and even reduce the damage you take.
But they don't dig as deep into the body's potential as your Breathing does. Instead of spending years trying to refine something like that, it's better to just train harder. Of course, if someone's already hit their limits, then researching something like your breathing might be worthwhile. That's why I say—Breathing Techniques are for the weak."
"I see."Ren nodded in realization. So that's the difference between worlds.
No matter how much a Demon Slayer trained, without Breathing Techniques, it was impossible for them to match a pirate's raw physicality.People in the world of One Piece had life forces as stubborn as cockroaches. Even those with only modest talent could, with training, lift massive boulders with ease. Their upper limit was leagues beyond that of the Demon Slayer world.
Thus, constrained by their human limits, Demon Slayers developed Breathing Techniques—shifting focus inward when external strength could no longer improve.Meanwhile, pirates devoted themselves entirely to raw physical training, rarely exploring internal control.
It was the difference in soil that shaped their destiny.
"So… does that mean the Breathing Technique is useless to you?" Ren asked.
"Not exactly."Zoro thought for a moment, then bowed seriously. "Your Breathing Technique gave me great inspiration. Creating a similar sword art from scratch would be inefficient for me. But if I can absorb elements of your Breathing and merge them into my swordsmanship, I might be able to reach a higher level.It's truly a brilliant sword discipline.Still, are you absolutely sure no one else in this world knows your Breathing Techniques?"
He clearly worried about accidentally stealing someone else's art.
"They don't. I can guarantee it," Ren said firmly.
"In that case," Zoro sighed with a rare smile, "I owe you another favor, Ren. Honestly… should I stick around and keep protecting you for a while longer?"
"We'll see when the time comes. There's still about a month left anyway."Ren rested his hand on Raichi's hilt and drew the blue blade. "I'm in the mood for a little exercise. How about a spar?"
As he said that, his crimson eyes flared with excitement.When you have a hammer, everything looks like a nail.But since there were no real enemies around—and ordinary ones were too weak to be interesting—Zoro was the perfect sparring partner.
"You're serious?" Zoro asked, surprised.
"Of course. I doubt anyone else in the East Blue can match your strength. A spar helps me find my shortcomings. Fighting weak opponents has no meaning. Don't worry about hurting me—you know how tough I am."
Ren grinned eagerly, fingers wrapped tightly around the hilt, golden patterns glowing faintly across his knuckles.
"I don't usually fight meaningless battles," Zoro muttered, then smirked. "But since you're the one asking… fine. Let's do this."
He couldn't bring himself to refuse; he owed Ren too much already.With a smooth motion, he drew Ryuen and Wado Ichimonji, his eyes turning serious.
"Then—let's begin!"
Ren lunged forward, crouched low.White steam burst from between his teeth like a boar preparing to charge.
Thunder Breathing activated—blue lightning flickered and coiled around his body like living serpents.In that instant, his agility stat leapt from F to E+—a whole tier of improvement!That was the terrifying power of Thunder Breathing when it harnessed every fiber of his body.
Under Ren's precise control, all that power gathered into the blue blade, compressing tighter and tighter—until it reached its limit.
BOOM!
Fourth Form: Distant Thunder!
The air itself trembled as blue light illuminated the dark valley.Ren's Raichi blazed like a streak of fire, and he shot forward at lightning speed.
In the blink of an eye, a blue bolt crashed down—CLANG!
Zoro crossed his twin blades to block, deflecting the lightning-wreathed strike with raw force.Using the recoil, he spun his blades and slashed upward.
Two-Sword Style: Dual Slash—Climbing Tower!
So fast!Ren's crimson eyes narrowed, but his body couldn't react in time.The blades cut cleanly across his waist, sending him flying backward.
Zoro dashed forward, both hands extended, blades angled like rhino horns.As soon as he closed the distance, he lunged.
Two-Sword Style: Rhino Return!
For an instant, his body vanished—only a lattice of white slash trails marked where his attacks had landed.Like a fisherman's net, the strikes enclosed Ren in a deadly cage.
But suddenly—Five streaks of blue lightning tore through the net, shattering the incoming slashes.
Ren kicked off one of Zoro's blades, using the rebound to leap high, then swung down with his Silverfall Dagger technique.The falling "meteor" exploded on impact, sword energy ravaging everything in its wake.
Massive boulders split apart cleanly.The ground cracked open with dozens of sharp scars, as though some invisible hand had carved graffiti into the valley floor.
Zoro, caught in the shockwave, couldn't evade in time.He switched stance fluidly—crossing both blades near his collarbone, the reversed grips forming twin horns.
Two-Sword Style: Bull Needle!
Dazzling cold light pierced through the storm, needlepoints shredding the oncoming sword aura.Even so, deep slashes tore through Zoro's clothes.
"Hey, hey… I've had this outfit for ages," he muttered dryly, still gripping his swords in reverse.Then, with his arms bulging, he thrust downward viciously.
Two-Sword Style: Dual Slash—Demon Bear!
The savage strike caught Ren just as he landed, both blades stabbing toward his collarbones.
No time to dodge.Ren channeled every ounce of power into one leg and unleashed it all at once.
First Form: Thunderclap and Flash!
There was no time to swing the blade—so he became the blade.A flash of blue thunder streaked through the air, hurling Zoro backward more than ten meters until he crashed into a giant boulder.
Ren didn't fare much better—his clothes were slashed open, exposing his lean, pale chest, two faint white marks crossing it.
Still not enough, he thought, sighing.With pure swordsmanship, he could only match Zoro's Two-Sword Style at best.Still, considering he'd only learned Thunder Breathing half an hour ago, this was already remarkable.
"Cough…"Through the swirling dust, Zoro pulled himself from the rock, walking forward quickly.As he advanced, he untied the bandanna on his arm and tied it around his head—his eyes gleaming with battle spirit.
In that moment, their gazes met.
Then—Ren calmly drove Raichi into the ground and raised both hands.
"I surrender."
(End of Chapter)