Interstellar Age - Chapter 52 Left To Die Alone

One day every human on the world suddenly receives a mail claiming to enact the World Salvation Project. Half in doubt Kurosaki Shion, a diligent university student and loner, follows the mail’s instructions, becoming one of a million Demon Kings governing his very own Domain in the new world.

*** This is a post-apocalyptic story containing many fantasy elements. It is a somewhat dark tale following Shion as he grows while aiming for the unification of the all too sudden new world. It has many game-elements bolstered by strategical thinking while at the same time providing funny moments and romantic encounters.

[Urban Martial Arts, Passionate Martial World.] He was a super expert who, due to accepting an inheritance, underwent a physical transformation that put his life at risk. To extend his life, the king returned...

The dawn era after the end of the half century has gradually rebuilt the order, abandoned civilization, and is full of undivided violence and desire.
The noble and powerful pioneers are in charge of the city, and the evil and mad plagues are in the wilderness.
Pure human beings who cannot mutate are the weakest, dominated by the rulers of the pioneers, and are not as good as animals in the wilderness.
A purely humanized young man with a worldly experience has quietly entered the WTO, holding a three-foot long knife and a long-distance desire to boil in the world of purgatory. From the nameless name to the sorrow of the Supreme Court, the name of the black ride is resounding!

- Description from Uukanshu (translated)

Zheng Tan somehow returns to the year 2003, turning into a black cat. Picked up from a rubbish heap by the Jiao family, he is given the name “Charcoal”, and so begins the life inside Professor Jiao’s family. Zheng Tan remembers that he was once a person, but currently his body is that of a cat. He has no way of speaking the human language, but can understand it, and even retains the thinking and IQ of a young 20 year old youth. Read along as he adapts to this new world, and somehow tumbles from a group brawl to catching a thief.

- Description from Novelupdates