Human-shaped creatures are the common enemy of all life. The Demon Clan is no exception.
These beings that know only slaughter absorb the Death Aura released when all kinds of living beings die to cultivate and survive. You could say they are demons among demons, the nightmare of all life.
The dense Death Aura is precisely their most iconic means of attack. If this truly was a human-shaped creature, then it would practically be a catastrophe descending.
Human-shaped creatures usually don't appear alone. Once they appear, it's in large groups.
To any living being, human-shaped creatures are synonymous with disaster. In the last dark turmoil, not only did the Human Race suffer heavy losses, even the Demon Clan suffered just as grievously.
This is a calamity shared by all life in this world, and also a taboo deep in their memories that they're least willing to mention.
