Flash Marriage: The Prince's Contract Wife - Chapter 613

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

King Grey has unrivaled strength, wealth, and prestige in a world governed by martial ability. However, solitude lingers closely behind those with great power. Beneath the glamorous exterior of a powerful king lurks the shell of man, devoid of purpose and will. 

Reincarnated into a new world filled with magic and monsters, the king has a second chance to relive his life. Correcting the mistakes of his past will not be his only challenge, however. Underneath the peace and prosperity of the new world is an undercurrent threatening to destroy everything he has worked for, questioning his role and reason for being born again. 

A boy that was imprisoned for millions of years has regained a mortal body.

He became a disciple of the declining Cleansing Incense Ancient Sect where its patriarch used to be his disciple. Now he will bring this sect back to its former glory.

This is his journey to reach the apex and take revenge on those who had imprisoned him.

This is his story of meeting old friends and making new companions.

This is his path of traversing the Nine Worlds and becoming the next ruler of the Heavens.

Several milennias have passed and the golden age of experts have passed. A master whose disciples once were the most exalted Immortals among the 9 worlds have all left him. With his mortal body, mortal physique and mortal life wheel. . . he shall sweep the 9 worlds and take what is rightfully his.

When Song Xiao was young, he wanted to become a Virtuous Official for a lifetime, but was forced to marry into the palace by that uncooperative Emperor; when his Virtuous Empress For A Lifetime career had just started, the Emperor died……