Transcendent Dawn - Chapter 470 - 0: Experiment (Extra 3600, asking for monthly pass)

In the foreign world, the martial artists dominate the world and the sword of the emperor controls the fate of hundreds of millions of lives! Long Yu, the number one killer on Earth, after dying, takes rebirth in this new world in an aristocratic family of martial artists but faces rejection because he is unable to practice martial arts.

- Description from Novelupdates

A world where the [Demon King] was defeated by a [Hero] that came from another world. People carelessly forgot about their fear of the [Demon King] and of monsters, living in peace.

In a forgotten and run-down cave in the mountains, a new monster that should not have been born was given birth.

The monster’s name was the [Black Ooze]. It was nothing exceptional other than its black color, an ordinary slime.

However, this slime had the special characteristic of being able to take the abilities of the living things it swallowed. It preyed on an insect that had paralytic poison, as well as other animals. Following that, it attacked a human, obtaining his knowledge and [Desire].

Before long, the monster established its target as the female mage that came to explore the cave.

This world still wasn’t aware.

As a precocious child, Lycoris suffers from a strange sense of deja vu. On the day her father told her about her fiancé, she realizes that her fiancé was a character from an otome game she once played in a previous life.

It started off peculiarly; first, his domestic cat refused to let him cuddle it.

Lin Qiushi soon found that a sense of disharmony and incongruity began to pervade everything around him.

Then, one odd day, he pushed open a door, and he discovered that the hallway he was familiar with turned into a boundless corridor.

At both ends of this corridor were twelve, identical iron gates.

Thus, the story began.

Ruan Nanzhu said to Lin Qiushi, “When you gaze into the abyss, the abyss also gazes back at you.”

Upon hearing this, Lin Qiushi sank into deep contemplation. He then pulled down the zipper of his trousers and aimed at the abyss…

Ruan Nanzhu: “…Put your pants on properly!”

Super shameless, ill, pampered gong X Shameless, calm shou; a combination of double [or extreme] shamelessness.

- Description from Novelupdates