Da Xuan Martial Saint - Chapter 821 - 449 The End of Heaven and Earth

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

Every drop of this family bloodline is stained with sin. They are the embodiment of contradiction; calm yet maniacal, with great memories yet often forgetful. They pledge themselves to their dreams yet often compromise, are angels that are also devils… It’s why I hate them. And also love them.

Hao Yan Che is an immortal and Yuan Gun Gun is a mortal.