Master of the Demon Emperor - Chapter 841: Emperor Su’s Time

Every “Diver” gets 96 hours on Earth before Thirstfall drags them back. Most return broken. Some don't return at all.Dryden Sands survived that loop for ten years—until he reached Rank-A... and got killed by the person he trusted most.But the Sacred Codex he'd found had other plans—it reset everything to Day One.Now Dryden remembers everything—hidden dungeons, broken rules, future disasters.But the System remembers him...And in Thirstfall, anomalies don't just struggle—they get purged.--------------

One day, Luo Jian woke up from his sleep and found himself in a locked chamber where the door and window were all sealed. A note with a few lines written on it was tacked to the wall: “Escape from this room within an hour, otherwise, you will die.”

There is a sequel called Reincarnation Night (轮回之夜) that takes place in the same universe but has different main characters

- Description from Novelupdates

Marlon, your typical bullied high school kid, fell into a pit on Earth and climbed out into Arden, a brutal world overrun by demonic beasts, monsters, and deadly extraterrestrial creatures that threatened humanity.In this world, humans could wield the apocalyptic energy called Aether to unlock systems and awaken supernatural talents to fend against the calamities.But Marlon’s new life began as that of a weakling, a laughing stock among everyone.Until fate handed him a rare, extraordinary talent: Absolute Attack.From a powerless outcast, he rose to become a heaven-shaking hero, his fists alone wielding unimaginable abilities—amplifying strength, healing wounds, bending reality, and even creating worlds.=====Join Discord: https://discord.gg/AMzKCWZp2x=====

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