Monster Factory - Chapter 402: Operation of Crystal

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.

“Zhong Nuannuan, your charges have been withdrawn. The courts have declared you innocent and pronounced you not guilty for murder. You can leave prison now. Your family is waiting for you in the waiting room outside.” Zhong Nuannuan was startled. She pushed the female prison guard to the side and ran toward the waiting room. She did not even bother to put on her shoes. If not for the icy feeling she felt at every step of the way reminding her that this was not a dream, Zhong Nuannuan would not have believed that she had resurrected.
As she burst through the doors and saw him again, she knew in her heart, that this time she would get it right. This time she would cherish him properly and hopefully, just hopefully, turn her own fate around.

Others treated disease to save person, he treated disease to steal heart.

The Frost Goddess was deeply captivated by him. The gentle and kind beautiful teacher was completely enchanted by him. Even the cold and beautiful female assassin melted quietly because of him.

Competing in medical skills? He was the one who treated the Godly Doctor. Competing with backgrounds? Leaders rushed to him. What? You actually wanted to compete with him in a match for match? Looking at the gentle girl beside him, Tang Yu had a headache as he said, “Beautiful girl, how did you fall in love with me?”

- Description from Novelupdates

A 30 year-old construction foreman and company worker, Satou Tarou dies from an unexpected accident. However, he receives a cheat-like ability from a god-like existence which allows him to cast healing magic and the knowledge to produce potions.

Using his newfound powers within this new world, Tarou accumulates a surplus of wealth and changes his name to Tauro. Setting his sights on the pleasure quarters of this parallel universe, perhaps the beginning of a new legend is on the rise….