MTL - The Five-year-old Milk of the Xuanmen Group’s Favorite Boss - Chapter 519 Missing case

In the vast Marvel universe, where superpower was still slowly growing in its infancy, several peerless superheroes tried to find their path in The Marvel Universe. A young adult named Ron from modern Earth unwittingly stumbles into such a world and begins his journey with an unknown power. This is a magnificent yet unknown true marvel world! This is the story of a normal young adult and his adventures!

- Description from Novelupdates

After waking up in the body of the Young Master of the Luo family, he finds he has the knowledge of hundreds of games and Light Novels. However, he finds his Dantian is crippled, so he can’t practice cultivation! Luckily, he has the Upgrade system.

Our protagonist Caam is a man from Earth that was reincarnated into this world as a demon. In order to survive, he spared no effort in avoiding the sparks of battle and without noticing it, he became strong himself.

Humanity was living peacefully on Earth for millions and millions of years until the day unknown monsters from beyond space invaded them.

When humans were about to disappear, some people with abilities came out to the light and shared their knowledge and powers with the world, and together, they managed to push back the invaders during a terrible war that had lasted for years.

This war had created many orphans, and among them, Kye had lost everything, even his parents. And the only thing he received from their death was a pale-looking necklace.

However, once the necklace finally activated, a system was given to him, and his life changed completely.

The system gave him quests to do, and Kye complied. He was getting stronger every time he achieved them, until the day it gave him a weird quest.

[You have one day to kill the one who had sinned. If you do not kill, you will die.]