MTL - Warhammer: The Beginning is the Crisis of Annihilation - Chapter 325 Slaughtering the Skaven (subscription required)

Zhou Yu is just an ordinary person. After his heart attack, he was born again. He thought he could enjoy life well, but he didn’t realize that this world was a supernatural world. He always bumps into ghosts and a group of samsaras would use him as a NPC. His lover always turns into a horror movie BOSS.

- Description from Novelupdates

She was forced by her husband and his mistress to jump into the sea and commit suicide, only to be rescued and taken care of by the jerk's uncle for seven years.

This is a world where humans, demons and mysterious beasts coexist.

Humans cultivate mysterious qi. Demons cultivate corporeal bodies. Mysterious beasts cultivate soul perception.

A legend says that in the middle of an endless rainforest, there are extremely powerful existences; they are called demon kings.

Some demon kings have a tyrannical corporeal body, some are experts in illusions.
Some demon kings are proficient in magic, some can even move mountains.
Some demon kings are able to sense things thousands of miles away.

These demon kings rarely appear in the human world. Even if they emerge in the human world, they would reincarnate in human form; assimilating with mankind while seeking to breakthrough realms…

- Description from Novelupdates

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.