I loved this story, the mystery was intriguing the love story was chilling and passionate. This one of those rare romances where the protagonist doesn't fall in love with a monster because there's a human heart within, he falls in love with the monster, period. He doesn't simply tolerate the grotesque nature of his lover, he is attracted to it.
I'm kind of sad to see that many people think the plot is too convoluted and that the plot twists are jarring, but trust me that's not the writer's fault, the translation really doesn't do this story justice. Sadly the botched japanese -> chinese -> english translation made it so that crucial plot points and foreshadowings were basically unintelligible, that's why nothing makes sense and everything seems like it happens out of nowhere. Truthfully everything about the story is clearly laid out from the beginning, as you can see chapter 1 literally spoils the ending, the entire story was planned from start to finish. I read the original web novel in japanese and it's so beautiful, I wish westerners could also see this work the way the author intended.