MTL - Ghost Marriage, the Abandoned Wife Has Three Treasures - Chapter 81 ：

The Student Council President’s Secret Laid Bare (生徒会長のセキ裸ラな秘密) is fairly standard 2D Dream Bunko fare but with an exhibitionism theme.

Basically, it’s about a guy who discovers the student council president is an exhibitionist and gets roped into helping her with that fetish.

Plagued with Prosopagnosia, Making friends or lovers was the last thing in Yujin's reach and on Yujin's list, after all, when the dream is to be the Strongest Being in the world, love doesn't even register, yes?

“W-wait... what's this? I am... Eugene? The same guy from that Eroge!?”

Unable to remember faces at all, will the petty villain in the Eroge be able to keep his dream of being the strongest in the world?

“Eugene...”

Or will this Eroge bring his chastity under threat?

A Steamy Erotic Comedy of the Strongest Person like none other begins now!

She is a waste daughter from the Su family that couldn’t cultivate. On the day before her wedding, the Third Prince breaks off their engagement in the street. Her own sister replaces her in the marriage to the Third Prince. She became the center of gossiping in the city. In her resentment, she hits herself on the Su Family’s gate, only to become the object of other people’s ghost marriage.

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