As the days went by, the ship/submarine started to get built, and Benimaru did it all by himself. At first, after making the keel, he then proceeded to create the engine that multiple sources of supply would power, as Benimaru thought that just purely relying on seawater could be a hindrance to his plans of exploring the moon in the future. So Benimaru made sure that it could run with flames, as Benimaru could generate endless flames, despite not having oxygen. The engine took around two weeks to finish, as Benimaru required metal for the engine.
After finishing the engine, Benimaru then created a thruster and propellers. Benimaru first created a small propeller that was designed based on the future references, which would create a forward reaction force that was caused by the pushing of the water backwards. Benimaru then amplified the strength of the material that he used by 10,000 times and amplified its size by about 100 times, so that from its original 5-inch diameter, it became a 500-inch diameter without the weight changing.
Benimaru then connected the propeller to the engine and decided to try the engine's ability to create thrust and propel the ship. When Benimaru generated a fire, he compressed it so that it would create a controlled explosion in the engine, and when it did, the thruster and propeller created a strong gush of wind that you would think was a stormy night. Benimaru was then satisfied with the results, and he continued building the ship.
Meanwhile, as Benimaru was building the ship, Camille, Viktor, and Jayce were continuing their training routine over the past two weeks. Benimaru amplified their muscle recovery and digestion, which made sure that everything they ate became nutrients for their body, and the results showed it.
After one week of continuous training, the three were now capable of lifting one ton for each limb, as Benimaru adjusted the weights that they were wearing. After the one-week adjustment period, Benimaru then ordered them to spar against each other to help them develop their fighting style, while prohibiting Viktor from using his Devil Fruit ability, which is something that he trained in his outside time.
As they sparred against each other, Benimaru noticed that Camille was adept at using her legs, as her peg leg had a longer reach due to its construction. Meanwhile, Jayce was fond of using a makeshift staff with a hammer-like head, something that Jayce created. Meanwhile, Viktor became great at using his fists, as he was used to making his fists into a rock.
Benimaru then created weapons for each of them using the Sea Stone door from the cave. Benimaru crafted a long leg prosthetic for Camille; he modeled it from the legs of Camille from League of Legends. For Jayce, he created a hammer that was capable of transforming into an electric cannon, similar to the Mercury Hammer from Jayce in League of Legends. And lastly, Viktor was permitted to use his Devil Fruit abilities. To make it interesting, Benimaru then gave them the written copy of the six martial arts of the Navy to learn by themselves, while offering them guidance if they had questions.
----------
As days turned into weeks and weeks into months, three full months had passed since Benimaru began constructing the ship. The timeline had stretched far beyond his original estimate, mostly due to his underestimation of the sheer amount of labor required. Even with his ability to manage the work alone, harvesting and processing the dense Adam Trees into usable planks proved to be a grueling task. True to his principles, Benimaru made sure that for every tree he cut down, another was planted in its place—its growth accelerated through his Devil Fruit abilities.
During his foraging trips across the island, he also discovered various medicinal plants and cultivated them aboard the ship, ensuring a sustainable supply of remedies for the future. To balance the crew's diet, he planted fruit-bearing trees—apples, tangerines, coconuts—creating a small but thriving garden on board. He was determined that not every meal should be built solely around meat.
Now standing before the nearly completed vessel, Benimaru allowed himself a moment of pride. The ship was a masterpiece of functionality and innovation. But what caught his attention even more was the transformation of the three individuals he had chosen to accompany him.
Camille, Viktor, and Jayce were no longer the same people from three months ago.
Utilizing a serum he developed from the blood of a Buccaneer and enhanced with genes from various island creatures, Benimaru had altered each of them to maximize their physical potential. For Camille, he had used the traits of a kangaroo for its explosive lower-body strength and a horse for its near-endless stamina. Her transformation was the most striking—her body now carried a powerful, Z-shaped form, reinforced by the prosthetic leg Benimaru had designed. It wasn't just for support; it was a weapon. Equipped with compact thrusters inspired by Iron Man's suit, Camille could now fly, darting through the air with precision and speed.
Jayce's enhancements leaned heavily into raw strength. He was infused with the genetic material of a rare gorilla species they encountered—an animal capable of effortlessly lifting 100 tons. Combined with horse DNA for stamina, Jayce had become a juggernaut of resilience and brute force. His strength, even among the three, stood out as overwhelming.
Viktor, meanwhile, had been enhanced with a hybrid of wolf and whale DNA, designed purely to boost his stamina. The changes allowed him to maintain his Logia Devil Fruit form for days at a time without rest. Though his strength was less flashy, his ability to outlast any opponent turned him into a formidable presence in prolonged combat.
With these upgrades—and the continual use of Benimaru's amplification abilities to boost their muscle development and recovery—the trio had, in just two months, risen to a level comparable to that of a Vice Admiral.
------------
Benimaru, Camille, Jayce, and Viktor stood proudly on the deck of their newly completed ship. The towering vessel gleamed in the sunlight, its body strong and sleek, a true testament to months of hard work. The only things missing were the sail and the pirate flag—symbols that would soon define their journey across the seas. But before that, they faced another important decision: naming the ship.
"What about BattleCruiser? Sounds manly, doesn't it?" Jayce proposed, flexing his newly honed muscles with an exaggerated grin.
Before he could enjoy any praise, Camille—noticeably taller now, her legs muscular and powerful from her kangaroo enhancements—lashed out with a swift kick to his face.
"Stop that. It's really annoying," she scolded, arms crossed. Jayce, unfazed, got up with a casual thumbs-up and a goofy smile.
"I think we should name it Camelot—after me," Camille suggested, her tone half-serious.
Unbeknownst to her, the name sparked instant groans from the others. In Benimaru's original world, Camelot was a well-known fictional kingdom, and the idea of naming the ship after a crewmate didn't sit well with the group.
"Boo!" Viktor added loudly, shaking his head. Jayce followed with an exaggerated yawn.
Benimaru, standing at the ship's helm, suddenly spoke. His voice cut through the bickering like a blade.
"Nautilus. That's the name of the ship."
No one dared argue. And they didn't need to—despite the abruptness of the declaration, the name resonated with them all. Nautilus. A name worthy of adventure, of the deep sea, of mystery and strength. It was perfect.
With that decision made, the four of them boarded the Nautilus, now docked on the shore of Whale Island. Behind them, the entire tribe had gathered to send them off. Benimaru's time on the island had gone far beyond building a ship. He had taught the tribe members Rokushiki techniques, administered animal-based serums to improve their strength and survivability, and introduced advanced farming methods to optimize their land and yield.
The islanders had benefited immensely from Benimaru's presence, and their gratefulness was evident in the tears that streamed down their faces as they waved farewell.
"TAKE CARE, EVERYONE! WE'LL COME BACK SOMEDAY!" Camille, Jayce, and Viktor shouted in unison, their voices cracking with emotion. Tears flowed freely as memories of shared meals, training, and laughter washed over them.
Benimaru stood silently at the back, watching the emotional farewell with a solemn expression. His thoughts drifted to the crew he had once called family—Law, Bepo, Shachi, Penguin, and especially Wolf.
I only spent two years with them... and I was bawling like a child when I left. I can't even imagine what they're feeling now, he thought quietly.
After about ten minutes of long goodbyes, the three finally stepped aboard the Nautilus. Benimaru activated the engine, which drew in seawater to begin the hydrogen-extraction process—its primary fuel source. Ordinarily, the procedure would take an entire day, but with a touch of his Devil Fruit power, Benimaru accelerated it, completing the process in under a minute.
He turned back one last time to face the people of Whale Island. "GOODBYE, EVERYONE! WE'LL SEE YOU SOON!" he called out, waving as the engine roared to life.
The ship stirred, the waves gently rocking beneath it, and just like that, the Nautilus embarked on its maiden voyage—carrying a new crew toward the horizon and a future filled with endless possibility.