Responses
All of them see the mc as an object for their own use. None of them see him as a human being, a person, someone with feelings and rights. They treat him like we treat inanimate objects--without regard for feelings, needs, pain.
Yule is both a sociopath and psychopath, his brother is legit insane, and his sister is very selfish and tries to hide it under a friendly demeanor. With every passing chapter, I dislike them more and more, especially Yule and his brother. His sister not so much, but since she wants to use Kyungsoo to make Yule more human at the expanse of Kyungsoo's happiness, sanity, and well being, she's no better either.