Valkyrie's Shadow - Chapter 3Before the Storm: Act 10,

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.

In Xu Yun Yao’s previous life, she overcame all obstacles barring her way just to become a queen. However, under the suppression of several ministers headed by Tang Song Nian she failed in the end. Just out of reach with bitter hatred in her heart, only to wake up and find herself reborn as the daughter of Tang Song Nian, as she died early.

Xu Yun Yao: I will trample you! You old fart! You dare to oppose this palace!

Tang Song Nian (laughing with joy): Aiya, our daughter’s boldness is truly too powerful.

Xu Yun Yao: I will kick you! I will bite you! You dare lead those ministers to slander this palace!

Tang Song Nian (gratified smile): I knew little treasure loves father best.

Xu Yun Yao: …….

- Description from Novelupdates

After forming a blood pact with the Saint and Demon ladies, the good-for-nothing young boy obtained the Yin-Yang divine veins, learned the art of alchemy and martial arts, and dominated the world.The young Shen Xiang had a romantic encounter with a goddess and a witch, and obtained their supreme inheritance, acquired a divine vein that defied the heavens, learned peerless magical skills, and mastered superb alchemy techniques, which made him very successful on the road of martial arts... When he was hungry, he would refine some pills as snacks, when he was lonely, he would flirt with the high and mighty goddess, when he was bored, he would play with those martial arts masters who came to ask for pills, and when he was tired, he would let the delicate wives around him give him massages...

Zhou Yu, a reclusive otaku, who did not like to go out of his house, was one day forced out of his house by a series of unexpected events.

- Description from Novelupdates