MTL - American Comic: Create An Oasis at the Beginning, and the Rise of Mutants - Chapter 87

Growing up in the slums, deprived of freedom, being enslaved by his parents and thugs, all Lucifer wanted was a life of freedom, a life that he could do whaver he wanted, not being ordered by anyone.And then luck came to Lucifer when he awakened the system, and even luckier was that he was able to raise his Destiny Rank to Unpredictable.But in return...he was turned into Freedom's Most Loyal Slave

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

Transmigrated to a wizarding world.'But... what about the promise of wizards pursuing truth?''Why is it just a bunch of greedy people who seek power!'...Passing guests, please come in and take a look; if it's not the right fit, then feel free to leave.

This is a story that follows the courtship between a stone from Hell and a god from Heaven that begins in the underworld and spans for three lifetimes in the mortal realm.