Demonic spirits do not eat flesh and blood. They eat names, numbers, language, and everything that humans use to understand the world. The devoured city-state will not be destroyed, but will be stripped away from reality, leaving not even ruins, leaving only unverifiable legends in the mouths of survivors.
Two hundred years ago, a huge tree root system fell from the clouds, penetrating the sky, digging deep into the earth, connecting the sky and the land: Since then, [Demon Spirits] --- a supernatural being that feeds on civilization, technology and knowledge. They gnaw at the names, laws and techniques that humans have established for the world, disintegrating order, making knowledge invalid, and the territory of civilization has become a lost land; survivors of the catastrophe cannot use [cognition] to understand them, and can only call them memes.
The so-called [cognition] is the way humans name, classify, measure and deduce the world. It is the boundary on which civilization is established; demons wander outside the boundaries of civilization and feed on the knowledge within the boundaries.
The last human settlement is standing on the verge of disappearing [understanding].
This is a war between civilization and forgetfulness, and it is also the story of mankind using its last [knowledge] to fight against memes.
