As Benimaru read through the entire diary, he came across a log that intrigued him. It detailed something he wanted to pursue for himself and the crew of the Heart Pirates.
[Day 1,504]The experiments have progressed smoothly. We managed to integrate only the advantageous traits of animals into humans. Using the serum enhancement and the incubation chamber, we were able to enhance a test subject's strength in proportion to the animal from which the genes were taken.
In our latest test, we successfully replicated the weight-to-strength ratio of a beetle in a human, allowing the subject to lift more than 1,000 times its weight. Muscle density was significantly increased, and overall potential was enhanced.
We will now begin developing a serum that combines the traits of multiple animals, without causing adverse side effects.End.
[Day 1,505]The first batch of the new serum produced side effects. The subject mutated into a combination of multiple animals: a lion's head, a goat's torso, eagle wings sprouting from its back, horse legs, and tiger-like claws for feet. The mutation began shortly after we inserted the serum into the incubation chamber.
Further modification is required to perfect the formula. However, this proves our hypothesis—we can create the perfect human-animal hybrid.
Perhaps in the future, we could attempt combinations of different human tribes: Lunarians, Giants, Long-Arms, Long-Legs, Tontatta, and Fishmen.End.
As Benimaru read on, his excitement grew. This was exactly what he had been looking for—something that could create a Zoan-like transformation without requiring a Devil Fruit.
Eventually, he reached the final entry in the diary:
[Day 5,005]We did it. Multiple animal traits can now coexist in a stable serum. However, combining human tribal genetics still results in collapse—unless limited to just two tribe traits. Any more, and the structure fails.
It's a dead end... at least for now. We're shutting the project down.END.
That was the final log in the journal Benimaru had been reading—a full record of what occurred during the experimentation. It thrilled him to know that what he had imagined was possible.
Benimaru then turned to the thousands of books on the shelves and began devouring them, just as he had with Wolf's books on mechanics. The first book he picked up offered a more detailed breakdown of the experiments: full logs, chemical compositions, formulas, and precise descriptions of each serum's effects.
After finishing the first book, Benimaru continued exploring the rest of the laboratory.
What he found surprised him. The equipment looked straight out of his past life—far more advanced than what should exist in the world of One Piece. The tech here clashed with the timeline. It didn't make sense.
He kept walking through different rooms. In one, he discovered parts of a ship and various journals scattered about. One research paper outlined a fire-powered engine—similar to the one Ace's boat had used—something Benimaru was confident he could replicate.
After reading through it in full, Benimaru understood how to design a more efficient engine. This was something he'd already been trying to do for the Heart Pirates' submarine—and now, something he could integrate into his future ship.
He found additional papers on weapons, and he read them all. Absorbing the information quickly, Benimaru took in every detail.
Two hours passed before he finished the last document. Among the papers, he found schematics for a mechanical arm similar to the one Zephyr used in the Z movie. That's when it clicked—this place had once been a Marine research facility… or perhaps even run by the World Government.
"If this were a World Government lab, then Saturn probably knows about it," Benimaru thought. "But if it's abandoned… maybe this was just a test site for the Seraphim project. Maybe Saturn doesn't even remember it exists."
After all, any science-related project under the World Government would ultimately tie back to the Warrior God of Science and Defense—Saturn.
Still, the thought stirred hope. "If this were a government lab… then there could still be Devil Fruits hidden here. Maybe even a powerful one."
Driven by that hope, Benimaru searched every nook and cranny of the lab. Along the way, he discovered several experimental guns and swords, all byproducts of the research conducted here. He also found something especially valuable: a non-edited Devil Fruit encyclopedia—one that included the real name of the Gomu Gomu no Mi.
Then something odd caught his eye. One of the bookshelves had a row of ten volumes arranged in a seemingly random order. The volumes were labeled: [3, 6, 9, 1, 8, 2, 5, 10, 4, 7].
Benimaru rearranged the books in numerical order. The moment he slid the last volume into place, a hidden compartment opened.
Inside was a safe, sealed with a padded 10-digit code lock. Without hesitation, Benimaru entered the digits based on the original book arrangement. The safe clicked open, and inside, there was a single key.
But it wasn't an ordinary key—it looked more like a cross. As soon as Benimaru picked it up, it flashed a red light and released a burning heat into his palm. Gritting his teeth, he refused to let go. After a few seconds, the heat stopped, and the key suddenly melted into his skin.
Benimaru stared at his hand in confusion. "What the hell…?"
Moments later, a nearby wall shifted, revealing a hidden door. A biometric scanner blinked to life. Benimaru pressed his burned hand against it, and the door opened.
Inside was the true prize: stacks of journals, fully developed weapons, and, most importantly, a Devil Fruit, sitting beside a final research log.