I’m Cultivating Immortality While Everyone Else Practices Martial Arts - Chapter 521 - Negotiations

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?

Aoki’s resolute face was indifferent. “If the sun doesn’t shine on me, please let me be surrounded by darkness!”
From a different perspective, look at the entire Pokemons world.

- Description from Uukanshu

The story is about a a hitman, Who dies because of his own recklessness and transmigrates into a game he used to play after his retirement as a hitman.I'm not gonna spoil any further, but i might answer few of your questions.Is MC overpowered?Nope, he'll become strong over time and all battle he'll fight will be because of his effort and techniques.Is there magic and adventure?Yes! It have both magic like normal isekai with adventure and fighting with monsters and many other things. There are other important things like “Essence Stone” But let's talk about it in the chapters.There will be harem?Not really, He will be in contact with many beautiful female and males but one waifu but i haven't decided yet.All i can say is, give it a try, I'll try my best to make it worth your time.

Zong Shou woke up from a dream and realised that he had time traveled back ten thousand years, to an era before the God Emperor was had appeared in the world.