First Legendary Dragon: Starting With The Limitless System - Chapter 30: Infinite Gacha

I became a professor in a game by accident. To make matters worse, I even messed up the difficulty settings. Now, I’m stuck playing on Hell Mode. A world on the brink of war with the Demon King. An Assassin Department where mu*der is legal… as long as you aren’t caught. I thought I’d have to claw my way through just to survive in this wretched place, and that was the case at first. But nowadays… “No matter how hard I try, I can’t be like you, Professor… How do you do it?” “Please… become our god.” “What do you know? What is it you know? Why do you make me want to live…?” One by one, everyone at the academy began to obsess over me.

Kirby Jon transmigrates to a parallel spacetime and is chosen to act as a bank robber in an exercise. Kirby Jon, who has obtained the God-level acting system, would receive a generous reward if he can act as a robber and attain an S-level score.

Doomsday comes, and human beings enter the heavenly world.
Ten years later, Yang Chen, who was betrayed tragically, returned strongly with the Tianyu bug. In this life, he vowed to make the betrayal pay the price. He has a powerful bug bonus, just like an open hang. Frightened to hear…

- Description from novelbuddy

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