One Piece: Curse of Immortality

(T/N: Please consider reviewing this Fanfic, Thanks and appreciate all who support me)

(T/N: Enjoy!!)

<><><><><><>

Rosinante, who had been pulled onto the ship, was soaking wet and had lost consciousness. 

His body was covered in wounds, and his exhaustion from that final burst of strength had completely drained him, causing him to fall into a deep coma.

Doflamingo silently looked at his younger brother lying on the deck, his emotions extremely complicated. 

He had seen the smile on Rosinante's face just before he passed out. He understood all too well what that expression meant.

Thinking back on the ten years his brother had spent in the Donquixote Family—pretending to be mute, hiding his strength, always keeping a stern face—Doflamingo's gaze flickered slightly. 

All of that, in hindsight, seemed to be an indirect testament to his failure.

But since Rosinante boarded this ship, his younger brother had stopped hiding his joy, his smiles now completely unrestrained.

"…Did he really bring you that much happiness?" Doflamingo muttered, falling into deep thought.

"Rosinante awakened Conqueror's Haki!"

Smoker and Buggy were both thrilled. Law also ran over, looking worriedly at him.

"Your Op-Op Fruit is the most suitable ability for a doctor," Arashi said as he walked over with a smile.

"A power that can only be used to save people… what's the point of that?" Law gritted his teeth. "What I really want is strength—true strength, like yours!"

If he had been strong enough, the tragedy of Flevance wouldn't have happened. 

If he had been stronger, Rosinante wouldn't have had to risk his life just to save him. 

He wanted to use his power to protect the people around him instead of always being the ones protected.

"Kid, don't underestimate your ability," Arashi said in a deep voice. "That was a power Rosinante traded his life for!"

"Learning to use it properly is the best way to protect the people beside you—now and in the future."

"Remember, true strength comes from yourself, not from your Devil Fruit."

"No matter how useless an ability may seem, if you push its limits, it can still shake the world!"

Law was taken aback. He was surprised by Arashi's keen insight but also lost in thought. 

If there was any "useless" ability, then the Silence Fruit fit that description. Yet, that so-called useless ability had saved his life on Minion Island.

"There are no useless fruits—only useless people," Arashi sighed lightly. 

His gaze fell on Rosinante, and he chuckled as if he had seen something interesting.

"Even the seemingly worthless Silence Fruit might one day rival the Quake-Quake Fruit."

Doflamingo's pupils contracted as he stared at his unconscious brother.

The Silence Fruit… on par with the power of the world's strongest man?

That sounded like pure nonsense.

"Take good care of Rosinante, kid," Arashi said. "Now that he's awakened Conqueror's Haki, his next stage of training can begin."

"Got it!" Law nodded firmly.

Then, Arashi turned to face Doflamingo.

"I'm a man of my word."

"You've fulfilled your part of the deal, so I won't be stingy with rewards."

After a pause, he continued, "Conqueror's Haki infusion… with your current control over Haki, you're still far from mastering it."

"But as for the advanced technique of Armament Haki—Flowing Sakura—I can teach you that."

Hearing those words, Doflamingo's eyes shrank in shock. He was completely caught off guard.

Was this man serious?

He had only just boarded the ship, yet Arashi was already willing to pass down such high-level techniques to him. Was he not afraid of being surpassed?

"But that will have to wait until we reach the West Blue," Arashi added. "This ship isn't exactly the best place for Haki training."

Doflamingo took a deep breath, his expression unreadable.

"…Thank you," he said after a moment.

He wasn't even sure why he had said it. He still didn't fully understand this man, but his curiosity about him grew stronger.

Three days later, the Marine warship crossed the Grand Line and passed through the Calm Belt, finally entering the West Blue.

Arashi still hadn't decided whether to head to Marine Headquarters to support Sengoku's promotion ceremony.

Deep down, he had a vague feeling that it wouldn't just be a simple formality—there was something more dangerous lurking behind the scenes.

Could Marine Headquarters be planning to take this opportunity to make a move against him?

That seemed unlikely, but still… he had plenty of time to think it over. There was no need to rush.

"Smoker and Buggy have already awakened Armament Haki," Arashi mused. "As for Observation Haki, that will depend on their individual talent and training."

"Rosinante, on the other hand, will be able to make significant progress in a short period of time."

Ten years ago, Rosinante had already developed superhuman physical strength and mastered the Six Powers. 

Now that his body had matured, he was naturally qualified to train in Haki. Half a day later, the warship arrived at the West Blue Marine Headquarters.

As they looked up at the floating fortress in the sky, Doflamingo, Law, Drake, and Rosinante all widened their eyes in shock.

"You didn't expect this, did you, Rosinante?" Buggy grinned smugly. 

"In these eleven years, the changes in the West Blue Marine Branch under Arashi's leadership have gone beyond anything you can imagine!"

Rosinante took a deep breath and followed the others onto the flying ship.

"It really is unbelievable," he admitted. Doflamingo, however, remained silent.

The massive sphere of lightning and clouds above the base made his mind race with speculation. 

The floating island… reminded him of a certain legendary pirate. His pupils contracted slightly.

Golden Lion Shiki… That man had disappeared from the world for a long time.

"If my guess is correct… Then this man… is terrifying!" Doflamingo's heart grew heavy.

For the first time in his life, his wariness of someone had reached its peak.

A master of Haki, the destructive power of the Rumble-Rumble Fruit… and if he possessed two Devil Fruits… Just how powerful was this man?

The thought alone was unfathomable. As they landed on the floating island, seeing the massive, bustling Marine base astonished everyone.

On the vast training grounds, the sound of battle cries echoed continuously.

Marines were sweating as they trained relentlessly. Their sparring matches were ruthless, each strike aimed at a vital point, making even the onlookers tense.

"These guys…"

"They might be even more elite than the Marines at Headquarters," Doflamingo thought grimly.

Then, his gaze shifted to the instructors overseeing the training. He fell silent.

This base even had a more direct, systematic training program than Marine Headquarters.

Combat techniques, swordsmanship, marksmanship—everything had dedicated instructors.

"Without me even realizing it… this man has already built an army of elite soldiers."

"He's not just some aimless warrior—he has ambition." Doflamingo clenched his fists.

No one who commanded an army like this would settle for an ordinary life. Moments later, in front of the main office building…

"Smoker, get them changed into proper uniforms!" Arashi ordered. "Be at the training ground tomorrow morning."

"Yes, sir!" Smoker responded seriously.

"And teach them Marine regulations while you're at it," Arashi added, glancing at the four of them, who still stood with undisciplined postures.

"Understood!" Smoker saluted.

As Arashi walked away, Smoker returned to face the three new Marine trainees.

"Alright," he said.

"Let me teach you guys what it means to be a Marine recruit!" Then, he glanced at the still-unconscious Rosinante.

"Buggy, take care of Rosinante." 

Buggy waved a hand dismissively and slung Rosinante over his shoulder. "Leave it to me! I'll make sure he sees just how much we've grown!"

Smoker chuckled.

He recalled the hellish training he had gone through when he first joined under Arashi's command.

"Times change, huh, Rosinante?" Smoker smirked.

"Looks like it's your turn now!"

"It seems that yesterday's brief training has already made you look more like Marines."

"Doflamingo, you've surprised me."

"A professional who truly dedicates themselves to their craft—I find that quite reassuring."

Doflamingo's expression remained unchanged, but inwardly, he was puzzled. Dedicates themselves to their craft? 

Was this implying that when he was a pirate, he acted like a pirate, and now that he was a Marine, he acted like a Marine? It sounded like a mockery. 

His eyes briefly flashed with irritation.

"Law, X Drake."

"You two just joined, so go train with the recruits."

Arashi turned to the two of them. Law and Drake nodded and walked away.

Yesterday, Smoker had already given them a base tour, so they weren't worried about getting lost. 

G-1 Base had four auxiliary islands and one main island, divided into various districts: a recruit training camp, designated residential areas, dining districts, entertainment zones, and bustling streets. 

This place was as prosperous as any island—no, it could even be considered a small nation.

"Starting now," Arashi said, his gaze sharp. "I will be giving the two of you specialized training."

Upon hearing this, Doflamingo and Rosinante's expressions became serious.

"Before that, there's something I need to say."

Seeing the questions in their eyes, Arashi smiled slightly.

"For many strong individuals in this world, simply possessing a Devil Fruit or pushing it to its limits is enough to make them powerful!"

"But for the true elites—the ones who aim to stand at the very pinnacle of the world—"

His eyes sharpened, and a torrent of Conqueror's Haki exploded from him, instantly engulfing them. Their faces changed.

"Haki is the power that reigns above all!!"

"If you want to become true powerhouses—"

"Then master your Haki first!"

Haki reigns supreme! This was a well-known saying from Teacher Kaido. 

Though right after saying it, Kaido had immediately demonstrated the terrifying potential of Devil Fruit Awakening, this never diminished the importance of Haki. 

In this world, ordinary people relied on Devil Fruits, the strong relied on Haki, and the truly monstrous ones combined it with advanced technology. 

Every top-tier powerhouse standing at the summit of the world had a mastery of Haki that was anything but ordinary.

Doflamingo and Rosinante trembled under the overwhelming force pressing down on them. 

The instant they felt its impact, they realized the gap between them and the man standing before them—it was like heaven and earth.

"Buzz!"

The vast and boundless Haki surged forward, majestic and overpowering, crashing down on them like an unstoppable wave, pressing against every cell in their bodies.

"He's concentrating his Conqueror's Haki on just our immediate surroundings, without affecting anyone else at all!"

"What terrifying control!"

Doflamingo was in shock.

By the second moment of impact, he instinctively released his own Conqueror's Haki to counteract it, and Rosinante did the same. 

Three forces of Conqueror's Haki clashed—but in just an instant, they saw the figure before them grin.

"Feel it for yourselves—the difference in our Conqueror's Haki!"

"Only by recognizing the gap can you set your sights on surpassing it!"

Arashi's eyes flashed, and an even more terrifying pressure surge erupted.

In that instant, their Conqueror's Haki was completely suppressed, forced back to only their immediate vicinity. 

Even the air around them changed color—turning black and red as they stepped into hell's depths.

"Impossible… I can't hold on much longer!"

Rosinante gritted his teeth. Despite his words, his eyes blazed with defiance, and he refused to back down.

Soon, the two of them realized the purpose behind this brutal pressure.

By enduring an even stronger Conqueror's Haki, they could experience firsthand the differences in strength. 

Through this, they could grasp the intricacies of control over their own Haki.

From unconscious intimidation… to deliberate restraint… this was an entirely new level of mastery. 

The final stage would be achieving an overwhelming quantity of Haki while refining its precision.

"Only under enemy pressure can you gain a deeper and faster understanding of your own Haki!"

Arashi's voice echoed around them. His arms were crossed, and from his very core, he unleashed an endless flow of Conqueror's Haki toward them.

"Awakening Conqueror's Haki means you already have a one-in-ten-thousand chance of reaching the world's peak!"

Sweat poured down Doflamingo and Rosinante's foreheads. Their entire bodies trembled, but they gritted their teeth and refused to fall under the immense force.

Only Conqueror's Haki could fight against Conqueror's Haki. Even though their own Haki was weak in comparison, it was still persistent.

"Try to control it—manipulate it!"

Doflamingo thought to himself. Soon, he discovered that he could slightly shift and condense his scattered Conqueror's Haki, making it more concentrated.

This filled him with excitement. But what shocked him even more—was that Rosinante had also managed to do it!

"This brat… he grasped it this fast?"

"He just awakened his Conqueror's Haki, and he's already figuring out control?"

His excitement instantly extinguished as if a bucket of cold water had been dumped on him.

The suffocating pressure lasted fifteen minutes before Arashi finally withdrew his Haki.

Both of them immediately collapsed, sitting on the ground with a thud.

"That's all it took for you two to break down?"

Arashi grinned, his eyes locking onto them.

"I told you, only when you face a true life-and-death crisis will you unleash your greatest potential."

"And that's what will push your Haki to grow faster!"

Doflamingo and Rosinante looked up, only to see Arashi standing before them. Their eyes widened in shock.

Before they could react, Arashi suddenly ripped off the upper part of his robe, revealing his scar-covered, battle-hardened muscles.

Then—his figure moved. Fast. Unbelievably fast.

In the blink of an eye, he was already above them, right over their heads.

"Fight me with the mindset that you could die at any second!"

Arashi's laughter echoed as he launched a punch toward them. Both of them, driven purely by instinct, sprang from the ground—dodging the attack by a hair's breadth.

BOOM!

The ground trembled. A massive crater formed where the punch landed.

"He's actually trying to kill us!!" Rosinante yelled in horror.

"If you've got time to panic, use it to figure out how we're going to deal with this guy!"

Doflamingo growled, his expression grim.

Despite their exhaustion, the two of them immediately shifted into combat mode.

"The so-called Armament Haki—"

"—is the ability to sense your own strength, spread it across your body like armour to boost defence—"

"—or coat it onto your fists, feet, and weapons to enhance attacks."

"More than that, it allows you to strike even Logia users!"

Arashi explained as he moved again.

His speed— It's still impossibly fast. It felt like teleportation, suffocating them with pressure.

"When a fighter reaches a certain level, this power will awaken naturally! The same applies—you can also master it through training."

"Smoker and Buggy both gained Armament Haki through training!"

Hearing this, Rosinante was taken aback. His former junior had unknowingly surpassed him.

"And as for Ryuo!"

Arashi lifted his foot when those words fell and kicked Doflamingo square in the stomach. Doflamingo raised both arms to block, successfully stopping the attack. 

A sigh of relief appeared on his face—but then, he caught the grin in Arashi's eyes.

"Ryuo is the flow of Armament Haki!"

"By making your Haki flow within your body, you can enhance its offensive power and project it outward!"

"You can strike a target from a distance, bypassing external defences and inflicting internal destruction!"

Doflamingo's pupils shrank. The next second, this man demonstrated the terrifying power of Ryuo firsthand.

Boom!

Doflamingo was sent flying backward. It felt as if his internal organs had shattered—pain coursed through his entire body, and he couldn't stop himself from spitting out a mouthful of blood.

"So this is Ryuo?!"

Doflamingo was in shock.

"It can bypass external defences and directly attack the inside?!"

Just the thought of such an ability was terrifying. It was like a stone—on the outside, it remained intact, but inside, it had been completely shattered.

"If you can make your Armament Haki flow…"

"You will master it!"

Arashi's voice echoed. In the blink of an eye, he reappeared before Rosinante.

His right fist swung out without any unnecessary movements, closing in on Rosinante's face instantly.

To Arashi's surprise, Rosinante—who originally had no chance of dodging—suddenly flickered out of the way, narrowly avoiding the strike.

"That was close!"

"If I got hit by that punch, I'd be dead!"

Rosinante gasped.

"Interesting!"

"You awakened both Observation and Conqueror's Haki at the same time?"

A smile appeared on Arashi's face. He stepped forward, throwing another punch.

Rosinante's eyes flashed red as he dodged, evading attack after attack, as if he could predict Arashi's movements ahead of time.

"Observation Haki is the ability to perceive others—their presence, their emotions, their intent!"

"At advanced levels, one can even foresee probable futures! It can even allow you to sense someone's thoughts and emotions. To awaken it… Rosinante, you truly have talent!"

Arashi smiled approvingly. But his attacks only grew faster.

After dodging five times, Rosinante was finally struck on the sixth, sending him tumbling through the air before crashing to the ground.

"In order to push you to your limits… Every single one of my punches is real. No holding back."

Arashi declared. At that moment, Doflamingo flashed forward, reaching him in an instant. With five fingers extended, he slashed downward.

"Five Color Strings!"

But the razor-sharp threads, which could cut through almost anything, snapped upon contact with Arashi's body.

"Use Haki! If you rely solely on your Devil Fruit, you'll always be a weakling!"

Arashi's voice was cold. Without hesitation, he slammed his fist into Doflamingo's nose.

Crack!

The sound of breaking bones rang out as blood gushed from Doflamingo's shattered nose. His signature sunglasses were destroyed.

"Don't make me repeat myself. For this training session…"

"You are only allowed to use physical combat and Haki! Fight me with the power of your own body!"

The chilling command echoed in the air. Rosinante didn't seem to mind, but Doflamingo's expression darkened—he was beginning to suspect that Arashi was targeting him specifically.

"The goal is to make you master Haki as quickly as possible!"

With that, Arashi launched another attack.

Doflamingo, though furious, was no fool—he had already started to focus on comprehending Haki, while Rosinante instinctively relied on his Observation of Haki.

"Ryuo! Let the flow of Armament Haki move through your body!"

Doflamingo took a deep breath. Gritting his teeth through the pain, he attempted to manipulate his Haki, guiding its flow with his mind.

Until now, Armament Haki had only allowed him to coat specific parts of his body for defense or to enhance attacks.

But after experiencing Arashi's Ryuo firsthand, he calmed himself and attempted to control it more precisely.

And at that moment—He saw it.

Within himself, a faint, swirling image of cherry blossoms fluttering and spiraling.

"I can see it!"

Doflamingo's eyes widened in shock. At that exact moment—

A foot slammed into his face, sending his head ringing as he was launched backward.

When he finally got up, his expression was anything but pleased as he glared at the figure standing before him.

"That's enough training for today! Tomorrow, we'll continue! This training won't end until you've fully mastered Haki!" Arashi grinned.

Training these two was, in a way, a great way for him to stay active—it was a rather enjoyable pastime. As for Smoker, Buggy, and the others? They had their sparring partners.

If you want to support me, join my patr**on. Have 10 advanced Chapters for you guys.

patr**n.com/saitamablast > OP:COI NOVEL TIER