The Surgeon’s Studio - Chapter 2951 I can't understand the situation.

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

Using the ability to freely travel between Earth and the fantasy world so he can… become a porter of two worlds…?

Bai Yang’s objective was to establish a production line that would yield hundreds of millions of pills, pellets, and artifacts…

- Description from Novelupdates

Seven days remained until the countdown to genetic mutation.Seven days later, all creatures on Earth would undergo mutations. Giant mutated creatures would swarm and attack humanity, putting their fate in jeopardy. The entire Earth would be ruled by these mutated beings!Yang Xiao accidentally walked into a genetic store where various gene potions were sold, capable of altering human body functions.From that moment on, he embarked on a crazy journey of genetic evolution.

Van and his friend Magus had reincarnated in another world with magic. Tasked to kill the demon lord, they set forth.Van was granted very rough skills that made life for him in that world a living hell, yet he muscled through.Magus however, was bestowed with unfair skills. Due to some of said skills, he gained a harem, which in time, included the girlfriend Van made in the world.After beating the Demon Lord, and after finding out his girlfriend had been stolen from him, he got very upset and so he went to propose to... The Demon Lord...!?