This would have earned another star if a certain someone was omitted from the story (we'll call it "Jeb Syndrome", after that controlling asshole from Splintered). 
 Right off the bat, I connected with Nyx. She is stuck in a family of jerks. (I am not saying my family is a bunch of jerks, because they're not, they're awesome. But I was definitely on her side instead of my usual "Oh, suck it up, you whiny, entitled teenager. Sheesh" spiel.) Her dad sucks, her aunt sucks, and her sister sucks. A long time ago, her dad made a deal with the Gentle Lord so that he and his wife could have children. Well, the wife died in childbirth because the Gentle Lord is huge on loopholes and stipulations (actually really loved that. Reminds me of Elijah from The Vampire Diaries / The Originals). So now Nyx has to marry the Gentle Lord while her twin sister gets to live a normal life. Oh, and daddy dearest starts secretly bedding his dead wife's sister. Classy. But Nyx, poor Nyx, has to study, train, and prepare herself to kill the Gentle Lord so that their land can be freed from the prison it was placed in nine hundred years ago. 
 Where this starts to waver for me is when Shade is introduced. Ignifex is awesome, a more accurate representation of a "bad boy" than seen in modern YA stories (he sleeps around! He drinks and smokes! He's a "bad boy!" Yeah, no). But Shade is shown as a sweet, innocent captive of Ignifex and then it all goes downhill. Nyx immediately falls in love with him for no reason whatsoever. She leans on him inexplicably for everything. 
 However, Nyx's interactions with Ignifex were way better. Their banter was great, and their relationship was build up out of initial hate and distrust into something fonder. This is something that could have been just fine without the bullshit Shade nonsense. And yes, I get that he's technically important and his existence makes sense, but really, if he had been cut out, more room could have been left for the plot. Instead, once Nyx enters the castle, the majority of the focus is on her relationship with Shade or Ignifex. It gets worse when she gains Ignifex's trust enough to visit her family and that immediately prompts her to turn against Ignifex because her sister is actually a devious little bitch until all that sweet naivety. Oi vey. 
 The last quarter of the book... ehhhhhhhhhhh. (view spoiler)[I understand why time was rewound. If it hadn't been, nobody in the village would have trusted Ignifex and then Nyx's HEA with him wouldn't have been 'perfect'. But the last bit was so draggy. At least her sister was more openly manipulative than her before-time-rewound counterpart, but I still hated her. And the aunt was even more obnoxious with her marriage to Nyx's father plus her baby bump. Basically, even without the Gentle Lord to fixate on, Nyx's family still sucked. Yay consistency. (hide spoiler)] 
 Cruel Beauty was still full of some pretty good stuff though, so I can in good conscience recommend it, even though I wasn't madly in love with it.