First Marriage, then love: wife, never divorce - Chapter 440

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

As part of the imperial family, every move by Chu Yuan in this game of chess is made with apprehension, fearing that with a moment of inattentiveness, the whole match will be lost in a single move. Ascending to the throne at eighteen, not half a year passes before civil strife erupts in Yun Nan. Though the thoughts of the old guard at the imperial court are not exactly identical, they are all waiting to see how the new emperor will put an end to this. Unexpectedly, before this side could make a move, a few thousand miles away, the King of Xi Nan, Duan Bai Yue, had already personally commanded troops to attack in all directions; not half a year had passed when peace was restored. Sparse moonlight shines into the palace; Chu Yuan stamped the wax seal himself, and had a secret letter sent urgently to Yun Nan 800 miles away — this time, what must we(1) give in exchange? Brush marks passed through the back of the paper; it almost can be seen, when writing this line, how angry the young emperor was. Duan Bai Yue spread out a piece of paper unhurriedly, replying with only one word. You.