Yan Jiu has a secret: he can see the darkness in others.
The 081 world is a world filled with malice.
When he was seven years old, everyone had different attributes, but he was the only one who didn't fit in. No one knows that he can see the black marks on everyone - they are traces of being eroded by darkness and a precursor to being forgotten by the world.
Until the man in the mask appeared.
They originally regarded each other as enemies, but that man's abilities were ineffective against Yan Jiu.
What Yan Jiu didn't know was that the masked man was his substitute teacher during the day, named Gu Sheng. And Gu Sheng didn't know that the "special person" he was looking for was none other than Yan Jiu.
A deeper darkness watches from behind.
And that darkness comes from Yan Jiu himself.
Intention: The real darkness is not in the outside world, but deep in the heart.