Book Eater - Chapter 2: The Greedy Grimoire ()

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

Mason was a mercenary, until the day he died on a mission after being betrayed by his unit.

Marauders shot Yuan in the head and buried him in a ditch. They thought it would be enough to put him down. They were wrong.Rising from the dead by the will of the Gun, demigod of revenge and firearms, Yuan only has one goal in mind: track down his murderers across the Unmade World and slaughter every last one of them. With the bullet-core stuck in his skull marking him as a Gunsoul, he can finally teach these arrogant cultivators a lesson they’ll never forget.But revenge isn’t so easy to claim. To carve out a path through the wasteland, Yuan will have to face power-hungry sects, nuclear cultivators, and weapon-gods. Let them come. No one will bury him again.He’ll give them all a taste of Bullet Hell.

Jiang Pengji got something called the Court Intrigue Stream System.
System: “Your goal is to become the most prestigious woman in the kingdom (the Queen)!”
Jiang Pengji: “Okay, System. No problem!”
Years later, she met the target by becoming the most prestigious woman (the Empress).
Jiang Pengji: “Well done, no?”

- Description from Novelupdates