The entire planet was reflected in a mirror that materialized in the sky.

The rest were monsters, with the exception of inanimate items. But Yang Yi is the only one who can see these creatures. Because… He is the sole administrator and the Mirror Authority.

Official version: The mirror is staring back at you as you are gazing into it. When Yang Yi raised his head, the self in the mirror appeared to be climbing out from the bottom of an abyss-like space in the air.

Original Webcomic