The way the author decided to pair Yura and Hajin is obscene and repugnant. There is the fact that the story depicted them having feelings for each other while she was still a child. Even though her time got sped up to a moment when she was fully grown, it doesn't leave a good impression at all. It looks like a mistake trying to be corrected for the sake of the reader, which instead got worse. The story had a lot of potential and originality; there is indeed the fact that the storyline was about devils, and by consequence some may think that some absurdplot turns may be pardoned,since it should defy logic and morals, but it really degrades the work's quality when such an approach is taken too far.

Art style is neat and certainly unique.
Humour was cool.

I have seen many opinions divided over this manhwa. Most of them scorned what happened within the 2nd season.
There are probably people who may still enjoy this work, despite some questionable turns of events, but most probably would not be able to overlook them.