The NPC sets out to defeat the demon king - Chapter 14

Having lived a normal life all his life and died without being able to fulfill his desire and when he’s given a task by a god, watch how he takes the protagonists girls while making it hard for the hero.

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

Bai Xunyin was inadvertently traumatized by stress during the year she graduated from Middle School. She became a “little mute” who couldn’t speak. In her first year of high school, she spent her days listening to the cynicism and discriminatory bullying of people around her until her second year of high school. Bai Xunyin met Yu Luoyin. He was clear, elegant, with straight eyebrows and star like eyes. He was the most handsome boy in school, and was the dream boyfriend of all girls in school. But for Bai Xunyin, Yu Luoyin was the first to protect her, smile at her, discuss topics with her, and the person who had lunch with her. The onset of her crush was turbulent and confusing in her teenage years.

Fate, a gatekeeper who had been working for the castle, is beset by a few burdens.