MTL - The World I’m Wearing is Wrong - Chapter 123 bullying

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

In the continent of Chang’an humans had lived as livestock and slaves to the Primordial Beasts. These beasts were ferocious, bloodthirsty and overwhelmingly powerful, but even so, the humans managed to prevail in the face of despair.

Forty years ago, demons invaded the eastern continent. Coming from another realm, they hunted the humans, and people soon began to wage war with them. Before long, there were those among the humans who inherited the demons' abilities.Demon hunters are currently the most in-demand profession. Although the chance of dying during a raid was high, the hunters were mostly popular among the common people. If you have some demon blood in your body, then the path to the Hunter's Association is open to you.Year 2066, Seoul. The territory of the former city is divided into three parts. Green Zone, Orange Zone and Red Dangerous Zone. Although mostly ordinary people and workers lived in the green zone, there was a chance for demons to get into it. That's why demon hunters patrol the whole area, sacrificing themselves for the lives of people.The main character, Lee Ki-hyun, inherited 50% demon blood and became the world's first SSS-ranked demon hunter. He will have to go through the path of a demon and learn the truth about his parents to save humanity.

This is a story of an ordinary boy gaining unusual powers from his nightmares… It all started when Lin Sheng experienced something strange on what he thought was just another normal day. He begins to have recurring dreams that lead him on an incredible journey of discovery as he encounters spine-chilling monsters and elusive secrets.

- Description from Novelupdates