After Transmigration, She Sold Herself to a Man as a Wife - Chapter 177: "They’re So Small."

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

No matter how twisted the world becomes, humans will always remain humans.In the face of their doom edging closer, their greed doubles instead of fading away. Their selfishness is unwavering—they simply want everything, even at the cost of endangering those closest to them.For that is the truth of humanity.So, if everything is linked to iniquities and sins, then unlike them, I won’t shy away from these possibilities—I will embrace them.---Synopsis:Kael, a young man from Earth—a dimension renowned for its technological advancements and brilliant minds—returns on a tour sponsored by his school.But fate has other plans.A Dimensional wave crashes into Earth, mutating the entire world into a grotesque landscape of unexplored horrors.Those who survived the dimensional impact awakened to newfound strengths, while those who didn’t perished—or worse—transformed into monstrosities far more fearsome than any beast.The world has returned to the law of the food chain. The strong will endure and rule, while the weak are devoured.Kael must cling to his sanity and navigate this nightmarish new world with a mission: to protect all he has left.But things take a darker turn when the system he acquired reveals an unexpected and horrifying backlash:{Consume human flesh}{Or perish within the next 24 hours}The clock is ticking, and Kael is left to grapple with an impossible choice that could seal his fate—or his humanity.

He’s in the deepest part of Jianghu.

Keep your eyes wide open.

If you do not wish to get dragged into the abyss.

Untolerated by heaven, a boy was restricted by the most powerful spell.

He accidentally acquired a painting inhabited by nine souls that claimed to be immortal.

Then, the legend of a strong young man who violated heavenly principles against the course of nature began.

- Description from Novelupdates