One Piece: Start with Zanpakutō

"It seems…"

"He's going to create something again."

When Zephyr saw Rosen's posture, he couldn't help but raise his hand to cover his forehead.

Back in the cafeteria, he had only asked Rosen to give a simple self-reflection. The result? Rosen directly comprehended the sixth Armament Haki technique — the Blut Arterie (Active Blood Dress).

Now on the beach, he simply asked Rosen to start learning the Rokushiki and Seimei Kikan (Life Return). And yet, once again, Rosen was messing things up in an unbelievable way.

Seriously.

Zephyr, known for his strictness and impossibly high standards — even Borsalino had been constantly scolded for being biased toward his fruit and "not working hard enough."

But for Rosen?

Honestly, Zephyr felt that Rosen could only be described as perfect in every aspect. There was absolutely no need for him to keep creating new skills, or to have breakthroughs at every disagreement.

"I just don't know…"

"What kind of insane surprise he'll come up with this time."

Although Zephyr felt Rosen's growth was already more than enough, he couldn't deny it — he was really curious.

[Your comprehension is extraordinary. Using your ultimate mastery of Haki as a foundation, through visualization and self-realization, combined with Zephyr's explanation, you have successfully deduced your exclusive physical skill: Rokugan Rebirth (Six-Organ Rebirth).]

[Rokugan Rebirth (Six-Organ Rebirth): Using Ultra Instinct-level Haki control, inject Armament Haki into the gallbladder, stomach, small intestine, large intestine, bladder, and triple burner, strengthening the six main internal systems. From this, create a perfect digestive system, capable of perfect nutrient absorption, enhancing physical strength, eliminating odor, preventing aging, and maintaining peak condition forever.]

(Requires ultimate-level Haki mastery. If anyone else tries, their organs will rupture and they will die instantly.)

Rosen didn't make Zephyr wait long.

After about half an hour, a piece of information appeared clearly in his mind.

The moment it appeared, he fully mastered everything about the Rokugan Rebirth (Six-Organ Rebirth).

"Now, I no longer have to worry about training my Haki and ending up harming my body from lack of nutrition."

"Whether it's Haki Practice or physical skills, with the Rokugan Rebirth (Six-Organ Rebirth)'s absorption ability, both needs can be fully satisfied — even with surplus."

"The most important part is… it stops aging and allows me to maintain my peak state forever."

A bright smile flickered in Rosen's eyes.

He instantly poured his Armament Haki into his internal organs. In that instant, his entire digestive system transformed into an insatiable monster that could digest and absorb anything perfectly and instantly.

In this pirate world, many substances contain extreme amounts of nutrition and energy, but ordinary human digestive systems can't fully break them down. Even just absorbing them is impossible.

But for Rosen now?

Anything that entered his stomach would be instantly digested and turned into pure nutrients. No residue left at all.

At that moment, he felt even the residual food in his intestines was fully digested, leaving his body completely clean.

The usual faint human body odor completely vanished.

Even if someone had a sense of smell a hundred times sharper than a hunting dog, they wouldn't be able to detect a single scent from Rosen.

More than that.

Through this perfected digestive system, Rosen could instantly deconstruct whatever he consumed and directly transform those nutrients into Haki energy and raw physical power.

No matter how badly he was injured — as long as he could breathe — he could recover through the Rokugan Rebirth (Six-Organ Rebirth).

In short…

Even air could become nourishment to strengthen him and heal him.

Combined with the Haki Core and the constantly self-Practicing Haki Seeds, his Three Forms of Haki would grow at a monstrous, exponential rate.

"Not just Haki."

"I haven't even started actual physical training yet, but my body has already begun strengthening itself on its own."

Rosen realized it keenly:

With the Rokugan Rebirth (Six-Organ Rebirth)'s perfect absorption, the massive nutrient supply wasn't just fueling his Haki — his physical strength and basic constitution were also improving rapidly.

It meant that even if he stopped training, stopped fighting, and just ate three meals a day…

His Haki would still explode in growth.

And his physical body would continue evolving toward a monster's level — steadily and endlessly.

"Rosen."

"Your aura… is rising."

"What's happening?"

Zephyr sensed it right away. His eyes gleamed red, and his Observation Haki spread out.

He could clearly feel that Rosen's overall presence was slowly but surely becoming stronger.

"Teacher Zephyr, didn't you just say that Seimei Kikan (Life Return) allows you to infuse your consciousness into every tissue and organ to freely control them?"

"So I thought, can I use this principle and combine it with Haki to create an even more advanced physical technique?"

"So I tried injecting Armament Haki into my stomach, small intestine, large intestine, gallbladder, bladder, and triple burner, to see if I could create a perfect digestive system."

"In the end, it worked."

"I call it… the Rokugan Rebirth (Six-Organ Rebirth)."

Rosen calmly and openly explained everything.

After all, the techniques he created were exclusive to him.

Even if he wanted to teach them to someone else, they would simply die on the spot.

Take the Blut Vene (Calm Blood Dress) and Blut Arterie (Active Blood Dress) as examples.

Injecting Armament Haki into the fragile capillaries to evolve attack and defense?

Who would dare to try that?

A single mistake and you'd die instantly from ruptured blood vessels.

"You… created your own Rokugan Rebirth (Six-Organ Rebirth) when I just asked you to learn Seimei Kikan (Life Return)?"

Zephyr instantly understood the power of this new skill, but because of that, he felt unbelievably complicated.

It felt like asking a junior high student to attend their first physics class… only to watch them build a working atomic bomb on the side — successfully.

"You keep this Rokugan Rebirth (Six-Organ Rebirth) to yourself."

"Just like your Blut Vene (Calm Blood Dress) and Blut Arterie (Active Blood Dress), don't even think of teaching it to anyone else."

"Injecting Haki into organs like the intestines and stomach… will 100% kill anyone else."

"No matter how close you are to them, don't teach it. Unless you want them to die."

In the end, Zephyr could only give Rosen this final reminder.

As a former Admiral, he understood everything the moment Rosen finished explaining.

The Rokugan Rebirth (Six-Organ Rebirth) completely overshadowed Seimei Kikan (Life Return) by hundreds of times. But because it was so extreme, it was purely Rosen's exclusive skill — absolutely non-transferable.

"I understand."

Rosen naturally knew how incredible these abilities were.

But because they were so insane, they naturally became unique to him alone.

In a way, he was glad.

Even if one day the Gorosei grew jealous of his talents, they would never dare to have any sinister thoughts about forcibly learning his skills.

Unless they wanted to kill every living being under their own command.

"Since you've created the Rokugan Rebirth (Six-Organ Rebirth), the problem of balancing Haki Practice and physical training has been perfectly resolved."

"So."

"I'll now officially teach you the Rokushiki."

Zephyr shook his head slightly, forcing himself to suppress the shock in his heart.

Then, he stepped forward and began personally demonstrating the Rokushiki right in front of Rosen's eyes.

...

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