Tensei Shitara Slime Datta Ken (WN) - Chapter 371

Rudel Arses, the first born of one of the ‘Three Lords’ of the Courtois Kingdom, is from a corrupted family, but at 5 years old, he saw a dragon in the sky and his dark future as a villain changed. He was considered an idiot, but was that true? How would his effort to become a dragoon change the kingdom?

As a true over-bearing president scum gong, when Xie He for the Nth time rejected his admirer, he heard a sentence in his head: “Congratulations on achieving the “rejects 100 hosts” accomplishment; as an award you will soon bind to the “Scum Gong and Cheap Shou” system, entering other worlds to complete capture missions.

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

Long Chen, a crippled youth who cannot cultivate, is constantly targeted and bullied by his fellow noble heirs. After a particularly vicious beating, he wakes up and realizes a Pill God’s soul has somehow merged with him, giving him some additional memories. Within those memories is the mysterious Nine Star Hegemon Body Art, a cultivation technique that even he can train in, but whose secrets and origin are still a mystery to him. Relying on his improved instincts as he finally begins to cultivate, he realizes a huge conspiracy is underfoot within the Phoenix Cry Empire, one involving his father, members of the imperial family, and even the Emperor himself.