MTL - Conan’s Devil Child Comes To the World - Chapter 489 size as desired

Earth Immortals are cultivated from a blessed land.

Shi Man was the best special agent in the organization, and she was supposed to retire in peace, but they came after her to purge her anyway. She died exhausted after turning the tables against the organization’s agents… but was reborn, transmigrating into a book as its villainess! The villainess’s family is rich and powerful. Being the only daughter, her mother and brothers would pamper her out of control, and she was engaged to the male lead at birth. Yet, the body’s original owner messed up big-time despite being dealt the perfect hand. She harassed the female lead to win the male lead’s attention and affection until she eventually incensed the male lead. He threw her into the colosseum ring, where she was torn to pieces. Her family naturally went all out to avenge her and ended up suffering multiple casualties as they fell into desperate straits…

On the other hand, when Shi Man reincarnated, she told the male lead that they should go their separate ways and pretend they never knew each other even if they met again. She even paid the female lead with emotional duress compensation and told her they had nothing to do with each other from then on. However, after parting ways with them and preparing to begin a new life, the male lead regretted his choice and started wooing her. The supporting male characters who were never interested in her also had a sudden change of heart, and even the female lead was now offering to be her follower! Staring at the mob flocking around Shi Man, the Shi family was furious. “She belongs to our family! Stay away!”

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