DxD: Strongest Dragon

Monkey D. Boa Issei

The World Government fell.

Im was defeated after centuries being the Absolute King, surpassed by the one who broke the logic of the world, Monkey D. Luffy, the man with powers over darkness and multiple other powers. The man who reached territory never before imagined, the strongest man in the world, that had surpassed all that came before him.

The Straw Hats, despite all their accomplishments and importance in overthrowing the Old World Government, were still infamous and feared throughout the world. Which was ironic, considering the contributions of some of the crew members. Among them, as one who wasn't exactly a member, but someone who practically lived with them, Vegapunk.

After the government's failed attempt to assassinate him, a failure, of course, thanks to the crew's interference, he had joined them, but purely out of his interest in continuing his research. And just like the current Pirate King and several others in the crew, he had fulfilled his dream.

The form of energy that was once lost was again discovered, and thanks to the scientist, it was spreading across the world, changing society as a whole. Not only that, but Vegapunk reached his goal, his finish line, reaching the same scientific level as the most advanced civilization in the world, the one that perished eight centuries ago, had. But his greed was comparable to that of a pirate.
And now, Vegapunk wanted to go further.

The ancient Kingdom, the society of the Lost Century, their science and wisdom were indeed very advanced compared to even himself a few years ago. However, they were still far from omniscience or anything of the like. Even they had limited knowledge, in the end. What Vegapunk now had set his sights on, was what was beyond the knowledge of the Lost Century.

"Little time, very little time..."

However, he was already an old man. Inevitably, his time would come... or was it really inevitable? He thought of a lot of things, easy when you're the most brilliant mind in the world.
He considered letting his original body pass and continuing the research with clones, but discarded the idea. If he were to continue advancing knowledge, he would want to do it himself. Then he had a bolder idea.

Immortality. It wasn't a fantasy, at least not completely. Im, centuries ago, had acquired it. As long as the idea of immortality existed, people's will and desires would make this concept manifest, in one way or another, after all, that's how Devil Fruits worked. In the case of immortality itself, the Ope Ope no Mi was the key, the fruit that was in the hands of one of the members of the Straw Hats.
Of course, it wasn't so simple, and there was a sacrifice to be paid if the user of the fruit decided to make someone immortal. It would end with his death. Those were the basic rules, but following Luffy's example, Vegapunk decided to take other routes, break the rules established by this world.

Cloning Trafalgar Law's fruit was relatively easy, the scientist already had countless amounts of practice with these things. The challenging part came later. He didn't want all of the fruit's abilities, just the ability to perform the Immortality Operation, and without the downside. It was somewhat challenging, and at the same time enlightening, the whole process of recreating a fruit based only on a single ability of the original fruit.

But for him, it was just a matter of time. Finally, he had created a unique fruit with the power to conceive immortality and placed it in an object, a weapon that utilized the energy of the Lost Century, meaning that it had infinite energy. In this way, the negative side of using the immortality operation had been overcome, and in theory, he could use it as many times as he wanted.
Now, it would only take one shot, and immortality would be in his hands.

Vegapunk was currently in his lab on the Sunny, alone, ready to take that giant step that would allow him to discover so much more about the secrets of not just the world, but the universe.