The Devil's Sleeping Beauty - Chapter 277 - Explanation

“Shit, is this really how I turn out?!”In the time of war he was known as the Body Flicker, Forbidden Magic Maker, and the Golden Blur.Arthur Vaelthorne.He had so many titles that it was unsurprising that the empire was the side that won the war, all because he had participated in it.A man that had the potential to become the strongest, rivaling the old powers, and the talent to back it up....Only ended up as a hidden boss in a popular game, meeting his end at the hands at one of his own students.A powerful hidden boss, unfortunately he had the fate of any other boss: Beaten by the protagonist.Now, with a second chance and the memories of one of the game's top players, he has a chance to rewrite his fate.

I thought the world was vast, for me to wander, but now, it has only become a cage. For a life unhindered, I wield a single sword to pierce the ninth heavens. People find me displeasing, but there’s nothing they can do. That’s the kind of life I love!“Stop! I paved this path and I planted these trees. If you want to pass through…”“Brother, I come from the Dustfallen sect.”“What? The Dustfallen sect! Piss off!”This pitiful sect was so poor to the point where even bandits did not want to waste time on it. However, how could this sect, these nine measly people, be ordinary? What you see is only what they wish for you to see. What you can’t see is the truth!Mu Yu—a young human boy with the powers of elemental demons—accidentally joins the impoverished Dustfallen sect. The sect that even bandits did not want to waste time on was actually hid great talents, concealing a huge secret! You look down on my sect? Then that’s your ignorance!

Perhaps it is the choice of fate. As a senior otaku, Qian Lingfeng got the “steel shell system”. However, when he swept the world with the system, became a local rich man, made all kinds of beautiful women, opened a harem, and realized the ultimate fantasy of thousands of otaku, he found that things seemed far from simple!
When the end comes, biochemical zombies suddenly come down, fierce beasts are in power, bloodthirsty zerg roam to kill the world, and human lives are comparable to dirt. Where will weak human beings go in this world? Is humanity going to be extinct? Or … can an otaku save the fate of the human race?

- Description from Novelupdates

The world is terrorized by the powerful Black Witch who has been sealed in the moon. Every ten years, the night of Hexennacht arrives and a chosen witch must battle the Black Witch in hopes of finally defeating her.

As the current decade’s Hexennacht approaches, a mysterious girl named Kagami Kagami arrives and meets Horinouchi Mitsuru, the daughter of the previous Hexennacht representative.

It takes place between Kyoukai Senjou no Horizon and the City Series, two other series by the author.