Demon King of the Royal Class - Chapter 18

I’ve possessed the mid-boss who tortures the protagonist and receives true education.Am I crazy? How dare I do such a thing to the person who is supposed to be the protagonist?I even planned to treat all the protagonist’s friends hospitably…“Everyone, wait for me! I will definitely become stronger and come to save you!”Oh. Running away.

Being able to learn any skill immediately, and just by raising its proficiency, stand at the summit.

He is the World Chef Association Honorary Chairman, having the title of the World Chef God.

He is the greatest composer, pianist, and conductor after Beethoven and Mozart.

He also has the title of Underground Racing King, Fist King, Gambling King, Giant of the Stock Exchange Market, Arm of the Industries and King of the Skies.

He who has a miraculous learning ability and can stand at the apex of all things if he so wishes for it, the Omni Genius.

- Description from Novelupdates

In an alternate world, a demon disrupts dynasties, harvests souls, and refines a banner of ten thousand souls.Under the heavenly tribulation, his body and soul are destroyed, but the Ten Thousand Souls Banner protects his undying spirit. Unable to possess a body, he's countered instead.A laid-back young man in society, wielding the Ten Thousand Souls Banner, roams the human world.With the Ten Thousand Souls Banner in hand, I refine a Golden Core with good deeds.A slice-of-life story with no ambition for conquest, helping the departed fulfill their wishes, gaining merit to repair the Ten Thousand Souls Banner, and enjoying a laid-back life.

A river song, triggered a legend of the rivers and lakes.
Tian Zun’s life motto: “My sword is the truth.”
Shen Lang’s life motto: “To serve people with morality, those who are dissatisfied are dead.”

- Description from uukanshu (translated)