Yasa knew the old man wasn't lying. The Thunder God's construction was indeed a monumental undertaking. Completing it within five years would be nothing short of miraculous, and he couldn't push for more.
"This is... infuriating!"
He rose from his throne, strode outside, and joined the shipwrights in their massive project of crafting the ship's components.
***
Time flew by like a fleeting arrow, and a year vanished in the blink of an eye.
It was the year 1496 of the Sea Circle Era, and Yasa turned sixteen.
Having grown another year, he now stood around two meters tall, his powerful physique hidden beneath his clothes, his muscles coiled like springs.
His appearance hadn't changed much, only becoming more ruggedly handsome.
Two meters was merely average, even slightly below average, height in the Pirate World, but Yasa was content.
His greatest transformation lay in his power. He had developed the Rumble-Rumble Fruit to two hundred million volts, matching Enel's output during his battle with Luffy, yet his destructive force far surpassed Enel's.
Amplified by electrical waves, his Observation Haki effortlessly enveloped the entire Sky Island, meaning every action of its inhabitants fell under his surveillance.
Yasa wasn't particularly thrilled by his rapid growth in power. He spent his days with the shipwrights, using electromagnetic forces to reshape gold into components for the Thunder God.
Thanks to their efforts, Yasa's mastery of electromagnetism had advanced significantly. With a mere thought, he could lift dozens or even hundreds of tons of gold.
Over the course of a year, all the gold from Sky Island was gathered at the edge of the Temple, where Yasa molded it into intricate parts.
When his Observation Haki enveloped Apayado, Yasa discovered the colossal serpent known as the Lord of the Sky, guarding the legendary Golden Bell.
Enraged by the God's Guard's attempt to seize its most prized treasure, the serpent rampaged, wreaking havoc across Apayado.
Had Yasa not intervened and subdued the beast, over half of Apayado would likely have been destroyed, requiring extensive reconstruction.
Perched upon his golden throne floating in the sky, Yasa rested his head on one hand while manipulating the scattered gold with the other, as if plucking the strings of a celestial harp.
Yasa's mastery of electromagnetic force had grown so refined that he could effortlessly reshape metal into any form he desired.
"It's been a year," Yasa mused silently. "All the components are finally manufactured. Now we just need to assemble them, but that will take another year or more. It's time for me to venture into the Blue Sea and meet the world's greatest heroes."
Crack! Crack!
Nearby the Temple, the slumbering Lord of the Sky shifted in its sleep, crushing countless towering trees beneath its massive body. The serpent's colossal form could likely coil around even the Whale Laboon of Reverse Mountain.
The Lord of the Sky had lived for over four centuries, once dwelling in the Blue Sea before being carried to Sky Island along with Jaya Island by the Upward Current.
Its body was striped with blue markings, and fish-like fins adorned its mouth. It was baffling how such a creature sustained itself, and why it hadn't devoured Sky Island in all these years.
Rows of trees were mercilessly flattened, leaving a vast clearing in Apayado.
"Jörmungandr, shut up and be quiet!" Yasa roared in annoyance.
Yasa had named it Jörmungandr, after the colossal serpent from Norse mythology that encircled the world. Bored, he'd given it the name because of its immense size and resemblance to the mythical creature.
Hearing Yasa's angry roar, Jörmungandr's serpentine body froze mid-roll, nearly retracting its neck like a turtle.
A year prior, when Yasa had gone to retrieve the Golden Bell, he'd fought Jörmungandr and beaten it so badly it couldn't even move.
Ever since, Jörmungandr had been genuinely terrified of Yasa.
"Hiss hiss hiss!"
Jörmungandr flicked its forked tongue at Yasa in a submissive gesture, lifting its massive head to nudge the throne in the sky.
Most people would have been terrified by such a sight, but Yasa was used to it. He knew this ancient serpent possessed intelligence rivaling that of humans.
"Alright, settle down!"
Yasa patted Jörmungandr's head and warned, "I'm leaving Sky Island soon. After I'm gone, you're in charge of these people, understand? If they slack off on shipbuilding, swallow them whole."
"Hiss hiss hiss..."
Jörmungandr nodded its head in agreement, assuring Yasa while a hint of reluctance flickered in its golden vertical pupils.
"Lord of Thunder, are you truly leaving?" Constance, who had been managing all the affairs of Sky Island for Yasa, no longer seemed as timid as before.
"After I'm gone, oversee the construction of the Thunder God. I'll make time to return and retrieve it in a year."
Yasa felt a pang of reluctance. After all, he had spent three years here.
But his ambitions could not be confined to this small Sky Island. The vast ocean offered a far grander stage.
"Should we inform the God's Guard to see you off?" Constance asked.
"No need. It's best if fewer people know about my departure."
Yasa waved his hand, his body slowly rising into the sky. He silently gazed down at the island he had ruled for two years.
"Though I commanded absolute obedience and held the power of life and death here, this isn't what I truly desire! I crave a thrilling life, the freedom to indulge my whims. Sky Island has always been too small for me!"
He cast one last, lingering glance at the unfinished Thunder God, his resolve hardening. With a final surge of determination, he transformed into a bolt of lightning and streaked westward!
Yasa's reborn family, the Shiboles, resided in West Blue, their castle built on a small island in the western sea.
He hadn't returned in eight years and didn't know if the family still existed.
Years ago, the family's trading expedition to the Grand Line had been lost in a violent storm, leaving only a few elderly, infirm servants and caretakers behind.
Most of them were likely dead by now. Even if some survived, the castle's valuables had probably been looted.
Yasa's sole purpose in returning to West Blue was to erect a memorial for his kind parents, to repay their nurturing.
People may lack righteousness, but they must never lack compassion.
His body fully transformed into elemental form, Yasa moved with the speed of thunder, soaring off the Sky Island in mere seconds.
His current physical prowess and stamina could easily sustain supersonic speeds and long-distance flight.
Unbeknownst to anyone, a streak of lightning was hurtling westward across the ten-thousand-meter-high sky toward West Blue.
The Pirate World was divided into four quadrants by the intersecting Red Line and Grand Line.
To reach West Blue, one had to leap over the Red Line toward the New World.
Yasa pressed onward without pause, reveling in his freedom as he weaved through the clouds. He cast aside the lingering melancholy of leaving Sky Island, replaced by boundless exhilaration.
It felt like a prisoner escaping confinement, suddenly free to roam the vast world.
"Hahahaha!" he roared with laughter, darting through the clouds. The lightning he left in his wake triggered a chain reaction, filling the sky with thunder and flashes.
The thunderous storm Yasa had stirred up would undoubtedly make life miserable for navigators, but what did he care?
A day later...
"Hmm? What's that over there?" Flying closer to the Red Line, Yasa spotted a dreamlike city perched atop the continent, shrouded in mist and clouds.
Clean, orderly, and lavishly opulent, it seemed to embody every conceivable beauty—a veritable paradise on earth.
"Mary Geoise?"
Yasa was certain that only the Holy Land Mary Geoise could occupy the Red Line's highest peak.
Suddenly, a wicked grin spread across his face. "Should I blast Mary Geoise with a cannon to announce my arrival, Kai D. Yasa, to the world?"
After careful consideration, Yasa decided against it. He couldn't fathom the secrets and horrors hidden within those walls.
After all, Mary Geoise had stood unyielding for eight centuries, a testament to some earth-shattering secret.
The fact that Doflamingo knew this secret and used it to blackmail the World Government, forcing them to tread carefully, was almost unbelievable.
"Never mind. I'll come back when I fear nothing. For now, let's return to West Blue!"
Yasa transformed back into a bolt of lightning and resumed his flight, soaring over the Red Line toward his homeland in this world.