----"Magus."
In short, they were beings born with magic, granted special powers by the world.
Put simply, they were the magi of this world—special individuals capable of using magic to fight.
About four hundred years ago, in other words, four centuries in the past, a race suddenly appeared in this world.
They were the natural enemies of humanity, savage creatures of unknown origin. They possessed a different kind of power from magic, allowing them to display unparalleled ferocity and aggression.
People called them—"Demon Scarabs."
Faced with these savage monsters, humanity was reduced to being slaughtered one-sidedly. In the end, for the sake of survival, people abandoned the ground overrun by Demon Scarabs and headed into the skies. Using magic and science, they built one Floating City after another, settled there, and made them the final fortresses against the Demon Scarabs, guarding humanity's last spark.
To humanity, the Demon Scarabs were not only sworn enemies but also a terrifying species.
That was because, in addition to possessing a different power from magic, they did more than simply kill. After killing humans, they could seize their existence and erase the memories of those around them regarding the deceased.
Thus, humanity feared the Demon Scarabs tremendously—far more than it hated them.
After all, people hated them because their important family members and friends had been taken away.
However, once someone was killed by a Demon Scarab, even their memories of their own important family members and friends would be taken away. Even if they knew that person had been important to them, they still could not feel much after learning of their death, because they had forgotten all the beautiful memories they shared with that important person.
For this reason, humanity feared the Demon Scarabs more than it hated them. No one knew