Synopsis :
Ren, a man from Earth, transmigrated into the world of One Piece.
Right from the start, he killed Enel and seized the power of the Rumble-Rumble Fruit.
He immediately proclaimed himself a god, took control of Sky Island, and discovered his ability to plunder Devil Fruit powers.
Soon after, he forcibly make Conis as his Godly Concubine.
The very next day, he noticed his physique had grown stronger.
After some research, he uncovered the reason and embarked on a path of capturing goddesses and recruiting Godly Concubines…
Ren never hid his true nature nor restrained his desires—he was greedy, lustful, power-hungry, and sought immortality to become a true god.
Since in Ren's eyes, the world of One Piece was already rotten to the core.
*****
Late in the year 1521 of the Sea Calendar.
[At this time, there were roughly six months left before Luffy set sail.]
Sky Island, Sanctuary [Upper Yard], God's Palace.
"Kami-sama, have you awakened? The dawn has arrived and the angels have prepared the morning meal~" A soft honeyed voice suddenly rang out.
Ren stirred awake and opened his eyes with satisfaction, glancing to the side.
Soon after, a tender, affectionate face came into his view—big, blinking eyes gazing playfully at him.
Her features were delicate and lovely, with lustrous golden hair styled into twin pigtails that stood upright, their ends deliberately shaped into spherical curls.
"Good morning, Conis," Ren greeted, stroking her golden locks.
"Good morning to you as well, Kami-sama."
Hearing this, Conis beamed, her eyes curving into crescents as she lightly tapped a small golden bell beside her.
A melodious chime echoed, and six Angel Attendants filed in, covering the dining table in the hall with sumptuous dishes.
After helping Ren dress, Conis was pulled close as they made their way to the table.
The angels stood on his other side, taking turns feeding him, earning a look of contentment from him.
This luxury had long become routine for him.
As he watched Conis, his [Godly Concubine], eating daintily beside him, Ren fell into deep thought.
Indeed, Ren was a transmigrator—and one who had arrived in this world physically.
This made him different from soul-transmigrators, as his body's structure wasn't the same as the natives of the One Piece world.
This meant his efficiency in strengthening his physique through training paled in comparison to the locals.
Fortunately, he possessed the Rumble-Rumble Fruit, allowing him to experiment with lightning tempering.
Ren waited and waited, but the anticipated "ding" of a system never came.
Just as he resigned himself to continuing his rule over Sky Island, he formed a bond with the beautiful Conis.
Their interactions brought him unexpected joy—because he could feel his body slowly growing stronger.
After his research, he discovered that only Conis possessed this ability, leading him to deduce that it could only be triggered by knowing the important female characters or supporting female characters.
So far, with Conis's help, he had managed to grasp the basics of Armament Haki.
However, the power of his current Haki paled in comparison to even a fraction of his Rumble-Rumble Fruit's might.
As for why he crossed over? Let's have a flashback a little.
***
Ren had just retired from his career as an assassins and was lounging comfortably in his gaming chair, watching Luffy's battle against Kaido in Wano.
He kept doing sit-ups in excitement until Luffy finally transformed into Nika.
[And why would an assassin watch One Piece…? Can't assassins have hobbies and entertainment?]
At this point, he couldn't hold back—awakening? Sun God Nika? Just like that and the rubber boy was gone?
Just as he felt another childhood masterpiece had been ruined, a melodious female voice suddenly whispered in his ear.
"Ren, wouldn't you like to experience the world of one piece freely?"
Ren thought he was hallucinating, but the next moment, he felt a pulling force yank him into a swirling black hole that had appeared beside him.
Faintly, he saw [three streaks of light] rush into his body before he lost consciousness.
When he woke up, he found himself in a sealed room, lying on top of something round and uncomfortable.
A white table in the distance held several apples.
He crawled aside and looked back—only to realize the "ball" beneath him was the head of a young man.
The youth wore a white headscarf, baggy pants, and had long earlobes.
His upper body and feet were bare, and thunder drums adorned his back.
With such distinctive features, how could Ren not recognize him as Enel?
He had literally crushed Enel to death!
(The residual spacetime energy from the crossover ignored Elemental Transformation.)
But that wasn't all.
Soon, Ren realized he could summon lightning and even transform into it.
Without a doubt, he had also stolen Enel's Rumble-Rumble Fruit powers.
Though bewildered, he had read enough transmigration novels to adapt quickly.
No one on Sky Island knew Armament Haki—this was a dreamlike start for him.
Thus, wielding the invincible power of the Rumble-Rumble Fruit, he effortlessly brought Sky Island under his rule.
However, the former god Gan Fall refused to submit to him.
Seizing the opportunity during the transition of power, he rallied the people of Sky Island to rebel.
How could Ren tolerate such defiance?
He promptly sent Gan Fall to join Enel in hell.
After electrocuting Gan Fall's steed, Pierre, into unconsciousness, Ren wondered if he could steal Devil Fruits like he had with Enel's.
He experimented relentlessly.
Eventually, he succeeded.
Using a white lightning technique, he extracted the Horse-Horse Fruit and sealed it into an apple, storing it in his collection.
Once he won over Conis, he had her hold his hand while he cautiously dipped his body into a tub filled with White Sea water.
To his surprise, he didn't got weaken.
From this, he concluded that his body wasn't of this world—somehow make him immune to the Devil Fruit's weaknesses.
*****
Two years into Ren's rule over Sky Island, the Ark Maxim was still incomplete, meaning Luffy's arrival remained some time away.
'The past two years were mainly spent familiarizing and developing my Devil Fruit abilities, as well as working hard to improve my physical strength.'
Noticing that Ren had lost his appetite, the angel beside him respectfully said.
"Kami-sama, the Shandia tribe submitted their letter of surrender yesterday. They are now awaiting your instructions."
"Tell Shura to have them meet me at the palace."
Shura, Shadley, Ohm, and Gedatsu were once the four priests serving under Enel, enduring his oppression which left them all somewhat mentally affected.
However, with Enel dead, their conditions have improved significantly.
As a trained assassin, Ren was well-versed in many areas, including the art of leadership.
Under his superior methods of control, the four priests were brought under his command, willingly pledging their loyalty to serve him.
Most Sky Islanders were docile by nature.
Unable to influence the change of gods, they could only pray that the new deity would be merciful and grant them a better life, thus submitting to him without resistance.
The Shandians, however, were stubborn.
Ren had no time to deal with them—he was too busy training daily to grow stronger!
Moreover, whether they were Sky Islanders or Shandians, in his eyes, they were all valuable labor forces who could dedicate their lives to him.
Losing even one would be a loss to him.
He only needed to focus on developing his forces peacefully.
Without lifting a finger, the Shandians would eventually covet the treatment of the Skypieans and submit to his rule.
And now, they had come.
...
Upper Yard, the palace.
The Shandian chief stood quietly at the foot of the grand hall alongside the warrior Wyper, awaiting the emperor of God's Nation.
Indeed, Ren was both the God of the Sky island and its emperor.