MTL - Billion Technology Crystal System - Chapter 3 : Sweeping the difficult list!

I accidentally changed the whole world, the resurrection of the dead, genetic variation, recovery of the qi, mountain and seas reborn, land and seas expanded and evil spirits have started to appear.

Ghosts are now commonplace. Some people now have three heads and six arms. Some people have obtained martial arts techniques and ordinary people are now just cannon fodder.

Fortunately, I have acquired an ability which can make various items mutate.

books into martial arts or cultivation manuals,

fruits into precious treasures of heaven and earth or poison that you can only imagine and…

weapons, that can split the earth or gain sentience!

- Description from Novelupdates

The idiot Long Gen pretends to be a pig and eats a tiger, takes advantage of the girls in the village, travels across the countryside and forests, monopolizes the beauty and coquettishness, and achieves the legend of “Dragon Gen”. There is a widow in front of the door leaning on the door to watch, and a sister-in-law next door looking through the screen window… This book is determined to be a stallion, with the goal of pushing down and being pushed.

- Description from novelbuddy

David became a pioneer in the Tiran Kingdom and acquired his own territory, becoming a village chief under the kingdom’s rule.

Although his land was located in a somewhat remote and harsh environment where crops were difficult to grow, and the village was only inhabited by him, David believed these difficulties could be overcome.

David declared, “My territory is open to all realms and dimensions. I won’t go looking for you; you come to me!”

- Description from Novelupdates

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.