Ancient Strengthening Technique - Chapter 3 Body Transformation!.

Pei Jiu picked up a girl by the riverside. He settled her on the mountain, and planned to send her back once she recovered. This delicate girl was a useless crybaby, so Pei Jiu had to be a nice person. He cooked her food and washed her clothes. He let the troublesome girl ride on his shoulders so she could pick fruits. During winter, he would warm up the bed for her. One day, she hugged Pei Jiu’s arm with a smile. “Big Brother Pei, you’re really an honest and a good man. I will marry you and give birth to your babies!”

Pei Jiu eyed her critically and scathingly enumerated her shortcomings. She was ignorant and spoiled. She only knew how to pester and flirt with people all day long. Give birth to babies? Go ahead, give birth to caterpillars.

The delicate girl bawled so hard that she passed out. The next day, Pei Jiu returned to his mansion and told his servants to prepare for his wedding ceremony. When he returned to the mountain in the evening, Pei Jiu opened the door as usual, but he found that the cheeky girl had disappeared. He searched the whole mountain for her to no avail. No one would act like a spoiled brat in front of him anymore. What a headache.

Note : 娇 (jiāo) : tender/delicate/pampered/spoiled

- Description from Novelupdates

He rose from abjection and achieved eternity in glory.
He embraced the prettiest beauties and killed the strongest opponents.
He was able to shift the clouds into rain and cover the sky with one hand.
He could overrun the entire world and go anywhere as he pleased.
He pacified wars and held the world in awe.
He was matchless in the world.
However, his hair turned white overnight for his beloved woman and he was on the verge of death.
He was surrounded by enemies who were trying to take his life.
He struggled his way to become mighty and fought for everything he cherished.
For this age, he was the only king of the Dark World.
His name was a byword for might.
As a man living in the world, his only ideal was to pursue brilliance.

The third young master of the Gu household, Gu Ye, had a wooden personality, a stuttering speech, couldn’t remember an answer after being told ten times, didn’t dare to protest after being bullied, was considered the shame of high society. His father, in a fit of anger, sent him back to the old home in the country for the new year. But unexpectedly, he came back like a new person, in half a year testing into the top university of the capital with the highest score in the whole school.

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