MTL - My Koi Sister is Three and a Half Years Old - Chapter 467 humble emperor

Civilization is destroyed and records lost. Only Dudian survives in a cryogenic sleep. Three hundred years later, Dudian wakes up and must become Dean to survive. Who can he trust in this world overrun by monsters without and within?

Mo Tianliao was a master weaponsmith and a demonic cultivator. When news spread that he was about to complete a divine weapon, cultivators from both the demonic and orthodox sides chased him down and killed him. In a stroke of luck, he managed to possess a new body and was reborn.

So what was the first thing on his mind after his rebirth? Avenging his death? Taking over the world?

Mo Tianliao: I have to find my cat!

—
Mo Tianliao: Why won’t you let me hug you? You used to be my cat!

Master: (unsheathes claws)

Mo Tianliao: Ahaha, this disciple has too much respect for Master, this disciple can’t bear to let Master walk on the ground!

Master: (lifts paw, sends disciple flying)

- Description from Novelupdates

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!

After the nuclear warfare, massacres started to spread throughout the entire world. The order between humans completely collapses, and the strong eats while the weak gets eaten becomes the #1 rule.