I Have the Alchemy Emperor in My Head - Chapter 2321 - : The Demon Prince

He is the ruler of the mercenary realm, an overlord that gives headaches to the leaders of any country! For the sake of his friends, he’s willing to sacrifice himself; for the sake of his family, he does not hesitate to spill blood! He is a dragon, one that soars above even the highest of heavens. He’s a power that advances triumphantly through unstable situations, stirring up both the winds and the waters.

- Description from Novelupdates

It was only after Su Yayan's death that she realized that she was a malicious cannon fodder female character who became a scapegoat in a Mary Sue story.

Zhuo Yifan was the Demon Emperor. One day, he managed to lay his hands on an ancient emperor’s book, the Nine Serenities Secret Records. As the book was coveted by many, he was targeted by experts and was even betrayed by his student.