10 nen goshi no HikiNiito o Yamete Gaishutsushitara Jitaku goto Isekai ni Ten'ishiteta - Chapter 1, Part 5: Yuuji, Attempting Food Security

The strongest Demon Lord dies, and reincarnates as a human. Not only that, he because of various incidents turns into the hero’s best friend.

Follow his journey as he tries to help the hero escape his fate, and on the sideline to conquer the continent while he’s at it.

They say the greatest blessing is marrying the idol you always dreamed of.

Chen Rui, an otaku from earth, is reborn into a human body in another world, who falls into the legendary evil, brutal world of the devil called Mozu where humans are treated as food. He has to survive while facing horrors of the devil, violent dragons and a variety of power enemies depending on a strange super system chip and his wits. Surrounded by Devil’s beauties such as black-bellied lolita princess, cold queens, violent dragons, charming poisonous devils …

Wanting to live in the Devil’s world is hard! Wanting to live in the Devil’s world as a human is harder! Wanting a human to be the devil’s son-in-law is hardest!

Let us see how a small otaku uses power and strategy step by step starting from an ordinary human to writing a legend as the devil’s greatest son-in-law.

- Description from Novelupdates

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