The so-called 'demons' are powerful entities that are neither real nor illusory, not bound by the laws of physics in the material world. Their very existence is a distortion of reality.
According to relevant research, demons exist within the Chaotic Abyss, the dark side of the universe, a pure energy world.
Demons can only enter the real universe under specific conditions, such as being summoned in a ritual, or when a rift from the Abyss appears somewhere. Even so, they cannot remain in the real universe for long.
If they must do so, they need to drag a part of the Chaotic Abyss into reality, overlaying a part of the real world, creating what is called the Demon World; otherwise, they must be bound to a host, which can be mechanical or a living being.
And the 'Great Demon' refers to the strongest among the demons.
The demons that bear this title are without exception the most terrifying enemies humanity faces.
