Ace's mastery over the Mera Mera no Mi was undeniably deep. From "Hiken" to "Dai Enkai: Entei," his control over flame had already reached a refined and destructive level. However, his Haki was comparatively lacking. After joining the Whitebeard Pirates, he focused more on responsibility and combat missions than on polishing his fundamentals, and even during the Paramount War at Marineford, he had not truly reached the absolute peak of his potential.
For Black, this made Ace an ideal sharpening stone.
He trained his swordsmanship methodically. He had no intention of becoming a powerhouse with inflated stats but shallow combat experience. In his previous life, he had seen too many examples of "high-level players" who missed decisive blows because they lacked real battle instinct.
Thus, even though the power gap between them was clear, Black deliberately dragged the fight on.
Inside the card space, flames roared and Haoshoku lightning crackled as steel and fire collided again and again. The battle lasted for half the night.
When it finally ended, Black stood in the azure System Space, an ability card materializing in his hand.
Ability Card: Conqueror's Haki (Young Ace)
"As expected of the Pirate King's son," Black murmured. "The drop quality is on a different level."
This was the first time he had obtained a Conqueror's Haki ability card.
Of course, that was partly because he had faced very few Haoshoku users so far. Strictly speaking, only Charlotte Linlin before this and her strength was far beyond what he could comfortably farm at the time.
"System. Use the ability card."
Without hesitation, Black crushed it.
In an instant, overwhelming Haoshoku erupted throughout the System Space.
Dark red lightning split the sky like divine punishment. Invisible pressure descended upon the ground, distorting the very air. The aura was tyrannical, heavy, and suffocating.
Black closed his eyes briefly and nodded in satisfaction.
After stacking Ace's Conqueror's Haki onto his own, the intensity of his Haoshoku nearly doubled. It was fundamentally different from before.
However, raw intensity and refined application were two separate matters.
Even if the pressure he released now was not inferior to someone like Figarland Shamrock, he still had not independently comprehended higher-level techniques such as coating attacks with Haoshoku or projecting it offensively over distance.
Black was not impatient.
Judging from how his Observation Haki had evolved, continuous stacking of high-quality ability cards would eventually allow him to naturally grasp advanced techniques like Conqueror's Infusion, long-range pressure bursts, or even Observation Haki suppression.
When he exited the System Space, it was already deep into the night.
His Kenbunshoku Haki spread across the ship.
Stella was asleep, gently holding Perona in her arms.
Robin sat by the window, gazing at the starlit sea. Her expression was calm, yet faintly troubled.
Today's events had undoubtedly shaken her world.
Black did not disturb her.
He turned over and closed his eyes.
Technically, training in the card space could replace sleep, but he did not feel an overwhelming urgency.
In his previous life, he had no choice but to grind relentlessly.
Now?
He was a Celestial Dragon.
If even after transmigrating into the world's highest aristocracy he still had to live like a desperate overachiever, then what was the point of reincarnation?
…
The world was vast.
But for those with identity, status, and authority, distance meant little.
Although most vessels in this era were sail-powered and some were even enormous island ships their peak speed under favorable currents rivaled high-speed trains from Black's previous world.
With a direct course set, it took only slightly more than ten days to travel from Ohara back to the Red Port beneath Mary Geoise.
Standing upon Mary Geoise's distinctive moving walkway, Black observed the reactions of those around him.
Stella remained composed.
Robin's posture was cautious.
Perona, however barely three years old fought to keep her eyes open, her gaze darting everywhere in wide-eyed wonder.
Black pressed a hand onto her constantly swiveling head.
"Behave in the Holy Land," he warned lightly. "Or I'll throw you down below to help push the walkway."
"Huh?!"
Perona and Robin both stared at him in disbelief. Even Stella's ever-present smile faltered.
"Are there really people pushing this from below?" Perona whispered, leaning forward as if she could see through the floor.
Robin's attention shifted elsewhere.
"With the World Government's technological capabilities, that seems… unnecessary."
Black shrugged.
"My foolish clansmen believe that such practices demonstrate noble superiority."
"In truth, it's nothing more than a rejection of technological progress and an extreme dependence on slavery."
There was faint disdain in his tone.
Position shaped perspective.
As a beneficiary of the system, he would never recklessly dismantle it. Even if he one day sat upon the Empty Throne, he would not disrupt the social structure without extracting greater strategic advantage.
Rulers did not indulge in moral impulses without calculation.
Perona nodded vaguely, half-understanding.
"So when we leave the Holy Land again… we can play freely, right?"
Black sighed internally.
Her priorities were impressively consistent.
Still, he did not scold her.
If everyone trembled before him in constant reverence, life would become unbearably dull.
Perhaps he did have a slight masochistic streak.
Upon returning to his manor, Black immediately removed the transparent helmet from his head.
"Finally. I can take off this damned fishbowl."
Stella accepted it with a smile.
"If Your Highness dislikes it so much, why continue wearing it?"
"Because," Black replied dryly, "I cannot breathe the same air as the lower world."
He paused, then added with a faint smirk,
"And I also have no interest in distinguishing myself over something so trivial."
He pinched Stella's cheek lightly and waved a hand.
"Go on. You've all been at sea long enough. I need proper rest."
He walked toward the enormous aquarium chamber within the estate large enough to contain ten thousand tons of water.
Inside swam a single mermaid.
On her left arm, the branded Hoof of the Celestial Dragons marked her status unmistakably.
It was the mermaid he had purchased at the auction house.
"Aida."
At the sound of his voice, Aida swam forward immediately, resting her delicate face against his palm through the glass barrier.
"Are you adjusting well?"
Her voice was soft and gentle.
"It's very spacious," she replied, nodding shyly. "The maid sisters talk to me every day. I'm… doing well."
She hesitated.
"It's just… sometimes they're busy, and I feel a little bored."
Her honest admission slipped out before she realized it.
Flustered, she stuck out her tongue playfully
Only to accidentally brush it against Black's palm.
Her face flushed instantly.
With a splash, she dove underwater, her tail sending ripples across the tank.
Black blinked, momentarily stunned, then chuckled.
"If you're bored, I'll find you a few companions next time."
He turned and left.
"Eh? Eh?!"
Aida popped her head back above the surface, but Black had already disappeared.
She slapped the water with her tail in mild frustration.
"Oh no… another one of my kind is going to be caught by this guy."
She pouted.
"But… he's only keeping me like this. It's not really betraying my people… right?"
After a strenuous session of self-consolation, the mermaid finally convinced herself.
Her guilt eased.
And soon, she resumed swimming happily within the vast, glittering waters of her gilded prison.