Hell's Handbook - Chapter 435

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

Ever since she transmigrated, she was blessed with an inbuilt anti-poison detector.

“Transmigrate as the Final Villain of the novel...” Ark stared at his reflection in the mirror he held. It was Theos Von Fallen, the final villain of his favorite novel.Although he was the final villain and the strongest in the novel, he was killed by the protagonist and his harem in the finale.[Ding. The Heroine Snatching System has started] Ark gave a crooked smile when he read the system message in front of him... “Exchange!” he shouted, unwilling to accept the fate they had in store for him.Trapped in the world of his favorite novel as the most “evil” and powerful villain, Ark, now Theos, will use his knowledge as a fan obsessed with the novel to take away all the protagonist's opportunities.Whether he can become the focus of the whole show or whether a script will dictate his fate, he will decide! He will live as a true villain who doesn't care about anything but his life and his loved ones.

Zhou Peng accidentally travels through time, finding himself in a weakened and sickly body with a shattered dantian, unable to cultivate qigong. Fortunately, the heavens show mercy by bestowing upon him an upgrade system.A waste? That's all in the past...Leveling up by slaying monsters, effortless and hassle-free, he no longer has to worry about cultivating.Killing monsters grants upgrades, and so does killing people. In the eyes of others, the awe-inspiring and prestigious sect masters are nothing but shining golden bosses in his sight...With the ability to upgrade, who am I afraid of? When so-called geniuses encounter roadblocks and fail to breakthrough, all I need to do is slay a few more beastly demons. Of course, sect heads, sect masters, realm lords... are even better.For the sake of my path to divinity, offer up your lives!