Evolving into a Great Dragon From a Koi Fish - Chapter 15

In one moment, he was walking down the street with his little sister—In the next, he had traveled to the world of One Piece, carrying a system that could extract, record, and fuse genes to cultivate powerful lifeforms.Thus began a leisurely and carefree life in the most chaotic world imaginable.When bored, he’d snatch a bit of heavenly tribute meant for the Celestial Dragons.When curious, he’d raise a few cute kittens and bunnies just for fun.When restless, he’d wander through the territories of the most fearsome powers in the New World.Life is beautiful—so why bother taking anything seriously?

He was on his way to buy some beer to celebrate his acceptance as a civil servant when he was suddenly isekai’d by truck-kun.

One god, one faith, one world, one mage… I am the only mage in the world.

- Description from Ptwxz (translated)

The heavens and earth change when the blood phoenix descends.