There are many legends that spoke of beings superior to humans that existed more than hundreds, maybe even thousands, of years ago.
They were called "Pure Bloods" because their blood had the ability to cure wounds, though according to writings they always refused to heal wounds this way unless necessary.
That and they were a purified version of demons.
Pure Bloods originated from the unity of the demon king and a human princess, and instead of bearing a half-demon, a purified demon with the appearance of a human was born.
They reigned for a very long time, until 93 generations, but like all empires they had their downfall.
And the biggest question remained unanswered…
"Why did they suddenly disappear?"
Their kingdom, their palaces, their military bases, they were nowhere in sight.
And in the ruins where the mighty race once stood and ruled over humanity, the only ancient record of their history was found.
A diary belonging to a Pure Blood who lived in the 90th generation, which was continuously passed down until the final generation.