Classroom of the Elite (LN) - Vol 155 Chapter 4.3: To Each Their Own Growth Part 3

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

Ethan Walker a normal boy was just playing his game favorite game [Legacy Of Heroes]. But who would've thought fate had a different plan for him.“Why him of all people!?”Transmigrated into the world of the game he takes on the role of Noah Von Blitzfeld, the younger son of the Blitzfeld Duchy, who was fated to die while saving his fiancee in a disaster unfolding in the academy.

This is a story about Gong Lixin who was the young master of an ancient underground palace in the ancient times. He was raised by his master and forced to partake sexual relationships with numerous people to cultivate his Yin Body. His master who has a Yang Body was going to absorb him after he has reach a level to become stronger. MC refused and killed his master also dying at the same time. Then he transmigrated to the modern time and thinking he will enjoy peaceful life, the end of the world arrived.