I Became the Little Demon in Leading Role's Family - Chapter 832 - 762: Love at First Sight, Until the Flowers Wither

One god, one faith, one world, one mage… I am the only mage in the world.

- Description from Ptwxz (translated)

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

On his coming-of-age day, Argolaith’s mistake bound him to a mystical magic unseen in the world. As his powers grow, they threaten to reshape the realm—but can he master them before they bring ruin?