ATG: My genius is almost frightening! - Chapter 243 - 242: Infinite Agony Soul Mark

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

System: You are now a lowly male supporting role, a passerby who wants to go offline at any time, please keep secretly and grow vulgarly.
Shi Yan: Very good, thank you for your suggestion.
The first world: Shi Yan, as a little prince born in a cold palace, made himself an emperor.
The original male and female protagonists, under his witness, became grudge couples.
The second world: Shi Yan, as the youngest son of the princess who died tragically, made himself a powerful minister over ten thousand people.
The original male and female protagonists, under his witness, became grudge couples.
The nth world: Shi Yan, as a genius in the world of comprehension, has made himself the number one powerhouse in the Three Realms.
The original male and female protagonists, under his witness, became grudge couples.
The system feels that something is wrong.
Shi Yan instead persuaded him: Let the male and female protagonists come together in the end no matter what the circumstances are, isn’t it the self-cultivation of the tool man and the male partner?

Content tags: Kuaichuan Shuangwen Metaphysics
Search keywords: Protagonist: Shi Yan ┃ Supporting role: ┃ Others:
One sentence introduction: The male partner is beautiful alone
Purpose: strong heart, unmoved by wind and rain

- Description from novelbuddy

A teenager who unexpectedly gets transported to the modern world from ‘the world of the immortals’ . He finds himself in the body of an ordinary guy. He wants to go back to his world and for that, he will have to practice to get stronger and investigate the reason why and how he crossed through to this world.