I had a hard time liking this novel for a long time. The first half of it comes across as nothing more than violence and rape to me. It wasn't sex, just violence. Take out the sexual intercourse and it would read pretty much the same. Just because Lu Cang was attracted to Jing doesn't mean Jing can do whatever he wanted to Lu Cang. The man was terrified of Jing and what he was capable of.
I'm a lover of BDSM but that way of life is based on mutual respect and trust between partners, none of which was in the first half of this story. Yes, Jing was a sadist. He got pleasure out of hurting Lu Cang. But with the way the story was written in 3rd-person subjective from Lu Cang's pov, it's obvious he wasn't consenting to Jing's sexual advances (he's not even a masochist! He never outright gets pleasure from the feeling of pain). Honestly, I can't condone stories which depict violence in such an obvious way for so many chapters and in the end leaves the reader thinking of it as sex.
I think for me, the biggest example of how there was nothing but violence in the relationship at the beginning is in the fact that the story does a 180 just over halfway through. As soon as Lu Cang decides he's willing, the sadistic play all but disappears. It's almost as if the writer couldn't write an SM couple properly - once there was love, they had more tender sex. Jing's sadistic need seemed to disappear which suited Lu Cang since he was never a masochist to begin with.
Basically, the first half of the story I found intolerable and the second half I found messy because I felt like I was reading a story about two completely new characters the way their relationship turned on its head. The rating I gave is pretty much due to the fact the story still flows fairly well and the development sans-rape/sex is decent, but be aware you have to stomach a lot of violence before getting any sort of romantic notion in the story.