This is one of those books where none of the characters ever have a satisfying conversation. It's all brooding and loneliness which can get on my nerves occasionally. At least have the POV character do something interesting with their time if you are not going to provide catharsis. Maybe if it had more world lore or something. At least overall the book was a quick easy read. 

Having Mal kiss that Zoya was heartbreaking. On top of that he's not sorry he hurt her, he's glad he got to rub it in her face. Except for the beginning of the story I get the impression that Mal doesn't really want to be around her, let alone protect her. Like if she died he would mourn not for a woman he loved but for having simply failed and having to feel guilty about it. Which makes me think he doesn't really love her. He never really shows it other than through jealousy and snipitz of friendly banter. But isn't having friendly banter with everyone his thing? After all this it would seem forced for them to actually end up happy together at the end. I hope one of them dies. 
An other issue is her "losing" her power at the end. It's the worst, most predictable chosen one challenges. 🙄