Erzhou's eyes are not dead, and he knows that he and Jiaki are in love because of the memory of "Light" and Jiaki. He tries to stay with Jiaki to protect him, but "Light" also has the memory of Jiaki. He cannot bear the life without Jiaki, so he goes down the mountain in the form of a monster to look for Jiaki, who has no impression of him and is afraid of him...
This is probably the story of the monster Hikari robbing Jiaki...
Purpose: Looking for love