In the year 1490 of the Sea Calendar, many major events shook the world. Among them, the most shocking was undoubtedly the murder of Admiral "Black Arm" Zephyr's (age 42) family by pirates, which led him to develop a deep-seated hatred for them. He began semi-retiring from the Marines, though he retained his Admiral rank, and later transitioned to become an instructor at the Marine training camp.
In the same year, the Magu Magu no Mi user, Sakazuki (Akainu), and the Pika Pika no Mi user, Borsalino (Kizaru), joined the Marines. With their exceptional strength and immense potential, they were admitted directly into the Marine training camp.
Also in this year, on April 1st, on a certain uninhabited island in the New World, the latter half of the Grand Line.
A three-masted sailing ship was moored beside the island. On its deck stood two individuals. One was a youth with white hair, brown skin, black wings, and a face still carrying a hint of immaturity. The other was a slightly plump young man with a bald head, sunglasses, purple lips, and a golden braid coiled on his head. He watched the intermittent tremors emanating from deep within the distant island.
"I say, King, what's gotten into Boss Kaido lately? This is the third small island we've come across in the past half-month. Every time, Boss Kaido goes on a rampage for most of the day," said the young man, who was not yet the fully-rounded Queen, puffing on a cigar as he spoke to King beside him.
"Our job is to obediently listen to Big Brother Kaido and wait here for him to come out. If you're truly bored, do as Boss Kaido said and train properly to improve your strength," King replied expressionlessly.
Even though they were now comrades, King still held no goodwill towards this man who, not long ago, had been conducting research on him.
With that, King directly flapped the wings on his back and took to the air.
"Hmph! Just a test subject. If Boss Kaido hadn't taken a fancy to you, I'd have continued my research on you long ago," Queen muttered with dissatisfaction as he watched King leave, his gaze involuntarily drifting back to the island that continued to rumble intermittently.
...
Meanwhile, in the central region of the island.
"Worororororo..."
The laughter was accompanied by massive tremors and roars that shook the entire island.
"Boom... Boom... Boom..."
Within the island, a massive azure dragon, stretching over a kilometer in length and dozens of meters in girth, tore through the landscape with an unstoppable momentum. Everything in its path was obliterated. Towering ancient trees and solid mountain rock could not hinder it in the slightest.
Finally, after a long time, as if having vented enough, the colossal form gradually came to a stop. It then raised its enormous draconic head high. Within its terrifying, lantern-like vertical pupils lay boundless excitement as it gazed at the dark ocean in the distance. It opened its maw, a yawning abyss, where fierce flames coiled.
"Boro Breath!"
"BOOM——!"
A breath of fire, several kilometers long, streaked across the sea, illuminating the entire world and causing the ocean to boil and steam.
A full minute later, the flames finally subsided. The gigantic body began to shrink, transforming into a man as tall as a giant—standing seven meters tall with a brawny, muscular build, every fiber of his body taut, and a black spiked club gripped in his hand.
As he swung the club, terrifying techniques intertwined with black and red lightning appeared one after another. Each strike caused the entire island to quake and mountains to tremble.
"Thunder Bagua!!!"
"Kaishin: Inazuma!"
"Kongo: Hanabi!"
"Shuku: Rindou Inazuma!"
"Kundali: Ryuseigun!"
"Borai: Hachibun!"
"Daidai: Raimei Hakke!"
...
Had he not restrained much of his strength and Haki, the entire island would have already been destroyed. Even so, the cataclysmic, heaven-and-earth-shaking power made it seem as if the island had endured a hurricane and storm of over level-ten magnitude.
After nearly three hours of this venting, everything finally ceased. The massive, burly figure plopped down onto the now-ruined ground, grabbed a huge gourd of sake nearby, and began gulping it down, glug glug glug.
Simultaneously, that joyful laughter rang out once more.
"Worororororo... Incredibly strong! Truly worthy of being the body of Kaido, one of the future Four Emperors of the New World, hailed as the King of the Beasts and The World's Strongest Creature! This nigh-indestructible physique, the power of the top-tier Mythical Zoan Type, Fish-Fish Fruit, Model: Azure Dragon, and this monstrously powerful Haki... it's all unbelievably strong!"
Kaido laughed heartily as he surveyed the island wrecked by his outburst.
Who could have imagined that an ordinary office worker from Earth, living a life of toil day in and day out, would one day wake up to find he had become none other than Kaido of the Beasts, a character from the manga One Piece—a series he had actually given up on following.
As one of the "Big Three" shonen manga, One Piece had once been one of his favorite series to follow.
However, ever since the plot entered the Wano Country arc, with its parade of twisted characters and endless, improbable recoveries, his passion for One Piece began to wane. Even his affection for the main protagonist crew started to fade. Instead, he found himself feeling a bit of sympathy for Kaido, the major antagonist of the arc—'Kaido-sensei.' But he also knew a villain's defeat by the hero was inevitable, so he didn't have particularly strong feelings about the final outcome.
Later, when the storyline involving the "Effort King" Koby appeared, it was the final straw that made him, then still an ordinary person, drop the series entirely. He only gained a rough understanding of the later plot from occasionally stumbling upon related videos while scrolling through short-form content.
But it didn't matter anymore. That was all decades in the future. Now, with his transmigration into Kaido, this world's storyline had already begun to deviate from its original course.
For example, King, who should have already eaten the Zoan Type, Dragon-Dragon Fruit, Ancient Model: Pteranodon, and Queen, who should have eaten the Zoan Type, Dragon-Dragon Fruit, Ancient Model: Brachiosaurus, had—due to his arrival—not consumed these Devil Fruits they had seized from the laboratory.
Moreover, since crossing over, perhaps due to his otherworldly soul acclimatizing, Kaido felt his body growing stronger. Not just ordinary growth, but an all-encompassing, continuous enhancement. The density of his bones, the resilience of his flesh, his reaction speed, his recovery rate... all had significantly improved.
It wasn't just his body. Kaido felt his mastery of all three types of Haki had improved by more than a notch. His Kenbunshoku Haki could now barely glimpse the future, though it was hit or miss. Both the quality and quantity of his Busoshoku Haki had markedly increased. And when he fully unleashed his Haoshoku Haki now, it could already exert a tangible effect on the physical world.
The current Kaido felt his present strength wasn't inferior to his future self during the Wano Country arc. Of course, this was just his own vague perception. After all, while he had inherited all of Kaido's memories and combat experience, making him no weakling, he still fell somewhat short compared to that future self. The main reason was likely a lack of experience fighting against Emperor-level powerhouses.
***
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