The Lucky Heiress - Chapter 111 - ill Wei Ruo angrily confronts Yun

[Shelter System successfully bound to host!][Option One: City of Light, save the survivors in the apocalypse and become a glorious and benevolent savior.][Option Two: City of Darkness, humans who enter the City of Darkness can only become your slaves. And you, will be the devil ruling over the apocalypse.]Sorry, I am no saint, I choose City of Darkness! From today onwards, I will be a villain!

In this world, orphans or just anyone without any hope for this world can apply to become a “walking target”. Their sole purpose is to be a practicing dummy for the students of the sect who train to become “Demon Hunters”. These students need “walking targets” to test their training on living, walking beings of flesh and blood.
In exchange, they will be provided with food & shelter.
Their existence value is lower than a slave, but if they manage to survive a few years they can receive a life long pension.

Xiao Han is such a “walking target”. One time he witnessed a powerful Demon Hunter disposing a demon. When the demon died, a fragment of the demon that managed to escape entered Xiao Han’s heart. No one saw that, and even Xiao Han himself only felt some discomfort for an instant.

But that thing in his heart soon gave Xiao Han visions, and the first one is of a cultivation method which allows Xiao Han to absorb damage to enhance his body. A perfect cultivation method for a “walking target”.

- Description from Novelupdates

Three years into Qin Yu's marriage, his wife and in-laws all hated him.