MTL - King of Classical Music - Chapter 19

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?

Jiang Bai woke up one day and found with shock that he had transmigrated to a parallel world that is similar to Earth. There, he was granted a cheat system to help him forge the path of a tyrant in this new world. He was now stuck in this parallel world body, the body of a weak and cowardly person. Join Jiang Bai as he rose to the top in this new world!

- Description from Novelupdates

When I cleared the final chapter of a game that was a national failure, I became an unnamed side character in it.

A non-standard, unmeasurable, EX rank supporting character.