If I Can't Be a Hero, I'll Just Become the Demon King

1: In a world where being a hero is a profession, becoming one is almost everyone's goal. Cang Shu, who has always been ostracized for his black hair and eyes, is finally declared a useless failure who can't become a hero after the hero aptitude test. The village that had adopted him abandons him. Then, during a heavy snowstorm, a delinquent who's always been jealous of the village chief's daughter's favor toward Cang Shu pushes him off a cliff, and he falls into the legendary Demon Realm. This world is completely different from anything Cang Shu knew. Though most of its residents look fierce and strange, they are unexpectedly honest and adorable. 2: For thousands of years, a prophecy has been passed down in the Demon Realm, isolated from the outside world: a black-haired, black-eyed stranger will become the new master of the unclaimed Demon Realm. He will bring all living beings under his command. He will be incredibly powerful. He will be the one and only Demon King. Yet after waiting for thousands of years, when the demons finally welcome their new Demon King, they stare at the frail boy before them, dumbfounded. The demons: There's no way we're admitting that this little runt, whose thighs are thinner than our arms, is our noble new Demon King! Later... The demons: It's... It's actually great! 3: As the only person in this world with black hair and eyes, fifteen-year-old Cang Shu has a secret no one knows. He isn't actually a native of this world. He's from a cultivation world called Qingyun. The youngest disciple in both seniority and age at the number-one sect in the Qingyun Realm, the Xuantian Immortal Sect, Cang Shu was born with the Sword Bone. From the moment he joined the sect, he was adored by everyone there. His senior brothers and sisters stuffed his storage ring with all kinds of heavenly treasures and miracle medicines, as if they cost nothing, afraid he might suffer even the slightest hardship outside. Unfortunately... Cang Shu, with nothing in his head but swordsmanship, was ambushed while exploring a secret realm. As he was breaking through, a tribulation lightning bolt hurled him into a dimensional rift, sending him to a strange world full of people with brightly colored hair and eyes. This place is rich in spiritual energy, but the people who live here don't cultivate immortality or pursue the Dao. Instead, they use spells that resemble those of spiritual cultivators. Cang Shu was born with the Sword Bone. His talent for sword cultivation is maxed out, but unfortunately his talent for magic is zero, so he fails the test to enter the world's most revered profession: hero. And so... Cang Shu: To fit in, since I can't become a hero, I guess I'll have to become the Demon King. [Reading Guide] * This is the story of a straight-laced sword cultivator transported to a Western fantasy world, where he leads the demons down the road to glorious madness. * The author's knowledge of Western fantasy comes entirely from anime, so the style of the whole story will probably be similar to Japanese anime. * There probably won't be a romantic pairing, because getting the male lead to understand romance would be too difficult. Theme: Here's to the passion and chuunibyou spirit that will never fade in our lifetimes.