The Ruler Of Darkness - Chapter 7Book 3:

“In a land far to the east, there exists a strange store that has rejected a three Michelin star rating multiple times.

[Congratulations! You are the Pioneer of the Mutation Abyss. Brace yourself - The Apocalypse begins now…][Main Quest: Eliminate Fellow Survivors][Description: The strong will thrive, and the weak will perish]Theo was never lucky. Bullied for his appearance and always underestimated, he lived his life as a pushover. But everything changed the night a meteorite struck him. His life takes a drastic turn.Chosen by the Mutation Abyss, he gains access to a mysterious system, granting him an evolutionary advantage.The world is doomed. An infection is spreading, turning the world into a deadly battleground. As the human Infectees mutate and portals to unknown realms open, otherworldly forces threaten humanity’s survival.Theo must harness his new abilities to survive in this brutal world. But in a place where strength is everything, will Theo keep his humanity, or become something worse?

After ten thousand years of cultivation, he could have achieved immortality. However, his lack of human experience led to his failure to attain immortality.Thus, he resolved to immerse himself in a century of human existence, seeking to enhance his journey toward immortality. What he didn’t anticipate, though, was that upon entering the human world, he would find himself cast as a son-in-law, facing disdain not only from his wife’s parents but also from his beautiful wife herself.Armed with a wealth of cultivation knowledge, how could he transform his drab human life?

A river song, triggered a legend of the rivers and lakes.
Tian Zun’s life motto: “My sword is the truth.”
Shen Lang’s life motto: “To serve people with morality, those who are dissatisfied are dead.”

- Description from uukanshu (translated)