Godclads - Chapter 13Book 35: Jailbreakers (IV)

The person that Pei Zhen hates most in his life is the perfect Fu Sichen. Alas, life is full of surprises and unpredictability. One fine day, an accident turns Pei Zhen into Fu Sichen’s pet cat! As Fu Sichen’s pet cat, he makes a shocking discovery about his sworn enemy – a deep dark secret that the perfect Fu Sichen has kept hidden for years. Trapped in his cat body, Pei Zhen moves from one adventure into another while trying hard to find a way of turning back into his human self. When he finally does, the world as he once knew, has become a completely different place!

In the end of the era, the ghost wizard was killed in a car accident, the soul crossed, and he found himself in Japan, and he was attached to a Japanese.

I was thinking about taking a name in Japan, and I picked up a newspaper and glanced at it –

Kudo Shinichi, Sherlock Holmes of Japan’s Heisei, the savior of the police? In the trough, how does Laozi wear into the world of the second yuan? Well, all in all, this is a story of a wizard playing a passerby in the Conan world…

- Description from MTLNovel

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!