One Piece: Nobody knows Devil Fruits better than me.

Chapter 43 Roy: I really need a Haki Devil Fruit, thank you!

"call"

Slowly retracting his fist, Zephyr gradually withdrew the powerful aura surrounding him.

The muscles throughout his body, which had been constantly changing with the flow of his domineering aura, slowly returned to normal at this moment.

Zefa's forehead was already covered in fine beads of sweat.

"I'm getting old."

Feeling the fatigue coursing through his body, the old man sighed inwardly.

This punch that cut off the deep-sea current was his full, unreserved effort.

By controlling every part of his body with the Black Body Flow and unleashing his maximum potential, his already unparalleled domineering aura can unleash incredible power.

He was able to maintain this level of performance for a considerable period of time during his prime.

But for him in recent years, such a blow has already put a great strain on his body.

In fact, it was the same when he encountered the pirate who attacked him at sea four years ago—Zeffa had almost overwhelmed his opponent when he went all out.

But that pirate survived thanks to his monstrous vitality, and only when Zephyr's body could no longer bear it did the tragedy that occurred four years ago happen.

According to the SSG scientists who examined him and prepared his new arm, in a few years, Zephyr's body may be completely unable to use the secrets of the Blackbody Style, and even sustained high-intensity combat will be very difficult.

This is the magic of time.

Even the most powerful generals who once dominated the seas will grow old.

Fortunately, though.
"There will be successors."

Zefa took a deep breath and turned around to see Loy's burning gaze.

He grinned.

"Boy, how are you?"

"Cattle."

What could Roy say? "That was it just now."

"The true essence of the 'black body' style."

Zefa said proudly, "First, temper your body until you can control every part of it, and then use that control to guide and master the domineering aura."

"When using Haki, one controls every part of the body to squeeze out its potential, in conjunction with one's Haki."

This is what makes his physical skills so special.

Many powerful individuals can achieve the ability to entwine themselves with Armament Haki.

Even among them, there are many whose pure Haki strength surpasses that of Zephyr.

But just like Zeff's punch just now showed—when Zeff threw a punch, it wasn't just Haki that was flowing.

Every part of his body was pushing its limits.

That's why his technique isn't called 'Black Wrist,' but 'Black Body'!
Therefore, Roy had no more complaints.

What else is there to say?
Let's practice!

Subsequently, under Zephyr's guidance...

Without hesitation, Roy found one of the countless surging 'black snakes' and leaped straight into it.

then
"!!!"

The pain returned.

However, this time the deep-sea pressure was different from the previous ones.

If the pressure of the deep sea was like a mountain pressing down on Roy's body...

This time, the massive ocean current in the deep sea was like a mountain growing out its fist and then punching it hard!
No, not a hundred punches!

"Boom!"

Roy felt that even though his bones and muscles had become as strong as steel after being equipped with the Quick-Cut Fruit, they seemed to be groaning at this moment.

"Hold on, feel the changes in your body, feel the power in every inch of your body—you have very poor control over your body, and most of your power is being wasted."

At that moment, Zephyr's voice reached his ears.

Upon hearing this, Roy gritted his teeth.

But just moments later, he felt a long-lost sense of exhaustion. His body relaxed, and like a withered leaf, he was swept away by the raging current and carried into the deep sea.

But at that very moment, Zephyr's figure suddenly flashed.

He instantly appeared within the ocean current, grabbed Roy with his left hand, and pulled him out.

Without waiting for Roy to say anything more, he said directly, "Part of the muscle is torn, but the bone should be fine. With your recovery ability—we'll start the next round of training in ten minutes?"

Upon hearing this, Roy gritted his teeth and laughed, "Seven minutes is enough."

"Good boy."

Zefa grinned, his expression growing increasingly pleased as he looked at him: "Seven minutes then—I'll go prepare some more coating bubbles for you."

After that, he turned and left.

Meanwhile, Roy calmly felt his body recovering in the deep sea.

His eyes were filled with determination at that moment.

He's usually a lazy guy.

But he never backed down when it came to times that required effort.

Seven minutes later, Zefa returned.

Without hesitation, Roy plunged headfirst into the giant wave again.

Once, twice, three times.
In this tranquil deep sea, Roy was repeatedly thrown into the air by the 'Black Serpent' and repeatedly pulled back by Zephyr.

"You use the muscles in your left calf much less efficiently than you use the muscles in your right leg."

Do you know why your shoulder blade broke this time? Because of what you just did.

"You need to engage your abdominal muscles further back; you need to feel it. Next time, try to control your strength to about 70%."

"That's right, that's it—you have to control your heart to pump blood faster."

"Keep going, keep going. How can you sleep at your age?" Zephyr also demonstrated why he was hailed as a legendary naval instructor.

Whenever Roy failed, he could almost always pinpoint Roy's problem accurately.

And through these repeated failures, Roy did indeed experience changes in his body.

The steel skin granted by the Cut-Cut Fruit seems to have become even denser after repeated tempering.

His mastery of the powers granted by the Giant Rhino Fruit and the Strong Fruit seemed to be gradually becoming more refined—he could even clearly perceive which muscle in his body had become stronger after being torn and repaired.

"I am getting stronger—I haven't added any Devil Fruit abilities, but I am definitely getting stronger."

Roy could clearly perceive this.

This allowed him to almost ignore his physical exhaustion and continue training like crazy.

Until one training session.

"Crack!"

Roy stood in the raging current, struggling to control his body against the massive surge.

His heart pumped blood faster, his muscles were completely engorged with blood, and he gritted his teeth, stretching out his hands to maintain his balance.

then
"Buzz!"

At one point, he felt a sensation within his body that he had never experienced before.

Roy found it hard to describe the feeling.

That wasn't a Devil Fruit ability, but rather a kind of power surging from deep within his bones and muscles.

It seemed to exist in every part of his body, like magma hidden beneath an underwater volcano.

But the feeling was so fleeting that Roy almost doubted it was an illusion.

So when the current swept him away again, and Zephyr pulled him out once more.

Roy couldn't wait to ask Zephyr what he had just felt.

then
"You feel it?"

Upon hearing this, Zephyr glanced at Roy, seemingly somewhat surprised.

"Of course it's not an illusion—what you're feeling is your own 'dominance'."

"really."

Upon hearing this, Luo Yi thought to himself, "Just as I thought: That's domineering aura?"

He had already guessed it—the power within him, though not a Devil Fruit ability, must be Haki.

But the problem is.
How do I use it?

Roy looked at Zephyr with some anticipation.

Upon hearing this, Zefa chuckled and glanced at him, saying, "What are you thinking, kid? It's not that simple."

He didn't hold back and directly shared his understanding of domineering aura with Roy: "Domineering aura exists within everyone, but the strength varies."

He held up his finger: "Aside from the fact that his innate Conqueror's Haki is somewhat special."

"The other two types of Haki can be acquired through training. The stronger a person's physique, the higher the potential of Armament Haki within them."

"The more acute a person's perception is, the higher their innate potential for Observation Haki."

At this point, he also pointed at Roy.

"Your body is as strong as a monster, so the potential of your Armament Haki must be ridiculously strong. It's normal that you can sense it so quickly."

"But feeling the domineering aura is only the first step—the key to cultivating the domineering aura is to hone and guide it out."

Hearing this, Roy was naturally somewhat disappointed.

"How long will it take me to cultivate my domineering aura? How long will it take me to reach your level?"

He really needs Haki—Armament Haki is indeed very useful when facing Logia-type Devil Fruit users.

Zephyr, however, did not hesitate: "It would take about half a year to initially guide the development of Haki."

"Even highly talented individuals would need one or two years to master the use of their inner domineering aura."

"As for reaching my level—well—with your physique and talent, you should be able to unleash all the domineering energy within you in about ten years. By then, you should have fully grasped the essence of the Black Body Style."

As he said this, Zefa's eyes were filled with anticipation.

In his view, Roy is not even thirty years old now.

In ten years, he will be less than forty years old, right in the prime of his life.

Zephyr was certain that Roy would be stronger than him back then!

'That Garp guy keeps telling me that Kuzan learned his Iron Fist. I'll show him just how strong the successor of Zeff really is!'

But clearly, Roy was stunned.

"It takes six months to cultivate that domineering aura?"

"It takes one or two years to become proficient? Ten years to reach peak performance?"

He could understand Zephyr's words—his physique was too strong, so his potential for Haki was also strong, and it would naturally take a lot of time to develop it.

Moreover, on second thought, even Luffy, who has maxed out his combat talent and is blessed with the protagonist's halo, spent two whole years training with a master of Haki like 'Dark King' Rayleigh before he mastered Haki.

In comparison, Zephyr's assessment clearly overestimates Roy's potential.

However, for Roy, this time was still a bit too long.

"Isn't there anything like a Haki Fruit here?"

He muttered this to himself.

But it's clear that Zephyr is unaware of Roy's thoughts.

So at this moment, after imagining himself showing off his apprentice to his old friend in the future, he looked at Luo Yi again.

"Have you rested enough? If you've rested enough, let's continue—ten more visits today and we can go home!"

"Ten times!?"

(End of this chapter)