The plot is something like this: The heroine falls in love with an abusive antihero. She's always attracted to him even when he insults and humiliates her. In the end, she forgives him because she finds out that he was sexually abused in his childhood.
I don't buy this plot as romance. It's more like a tragedy, which many victims of domestic violence experience in real life.
This plot is very familiar and Cole has already used something like this in my favorite book in the Immortals After Dark series, namely [b:A Hunger Like No Other|14384|A Hunger Like No Other (Immortals After Dark, #2)|Kresley Cole|http://d202m5krfqbpi5.cloudfront.net/books/1357616154s/14384.jpg|16422].
The heroine here had great potentials; She had a very severe case of sex addiction and would physically suffer from lack of sex. She was also very proud and initially refused to debase herself in order to have sex. Unfortunately, she chooses to remain a victim. Our abusive antihero overcomes his problems mostly by himself and the heroine provides little help in that matter. (Victims usually do not help oppressors.)
Sex scenes were tedious as hell and I preferred to skip through them. In the final chapters, these scenes became even ridiculous to the extend that they were considered medicine and the antihero was shown as selfless and kind for fucking the poor girl.
Right now I have serious doubts about continuing this series. All the stories have become Nix's doing and the main characters are just pawns in her games. I don't like this Nix and I hate the idea of fate and all.