Vampire Academy, anyone? 
 Where do I even begin? I started this book without reading any reviews or even the blurb (yeah, I'm that reckless), just saw the high rating and decided to jump in on a whim. 
 And it would have been a good story, except that this turned out to be a twin of Vampire Academy, and all the similarities really pissed me off. You see, that is the exact reason I refused to read the Half-Blood series, I hate rip-offs. If I'm a fan of VA, it doesn't mean I want to read the same story again and again. I want the original, not the copycats. There are people who are able to overlook such things and enjoy the story all the same, but I'm just not one of them. 
 The main character of this book, Kendra Irisavie, is like Rose and Lissa rolled into one. She's got Rose's attitude and fighting skills, but her magic gift is very unique and rare (she's an Empath, able to see people's feelings and emotions) and she belongs to a "royal" family. 
 Then we have a selkie prince and guardian gardinel Tristan Belikov Belicoux, who is practically a carbon copy/ lookalike of Dimitri. The first time he is introduced in the story, he wears a long leather jacket, too, I kid you not. Also, he has this weird penchant for country cello music. 
 Then there is Adrian Ivashkov Julian LeVeq. The first time he meets Rose, oops, I mean, Kendra, it is basically the same scene from Frostbite. 
 There is also a Mason, an Eddie, a Jesse Zeklos, a Mia Rinaldi, and I'm sure I'd encounter many more familiar characters if I decided to continue. 
 Aquidae demons play the part of evil Strigoi. People can be turned Aquidae the same way they can be turned Strigoi - "Aquidae were humans or elementals who were turned, either by force or by choice. Once injected with the dark essence of the Shadow, their mortal lives were extinguished. They existed as an empty shell, a vessel for the demonic liquid." I don't completely get the purpose of Aquidae, except that they are soulless evil creatures of Darkness who get off violence, chaos and destruction and want to annihilate all ondines ... why? According to the lore, ondines are responsible for protection and maintenance of water. What does that mean, exactly? There is also mention of some other elementals (Fire), but they were never explained. I really would have liked to know more how the magic world functions *sigh*. Maybe there were more explanations later in the book. By the way, Aquidae can be killed only with a silver stake kouperet (obviously, some kind of knife), infused with the magic of all four water elementals. 
 I think the supernatural world was very poorly rendered. It was all over the place, and at 30% into the story I still didn't know for sure who was who and what role they played in the society. So, they are all Water Elementals. I guess ondines are all females, while selkies are all males, and demillirs are like dhampirs in VA, half-bloods. There is also a mention of dessondines ??, who are both ancestors of ondines and demillirs, and they supposedly exist in the present too, but I never met one during the 30% of the story I've read. All the groups of elementals are not immortal, but they normally live long and healthy lives (about 150 years). 
 Only ondines are at risk, it seems. And here's why it sucks to be an ondine - if her husband cheats on her, she will get sick and die. She will also age prematurely, get sick and die if any of her children dies. WHAT THE FUCK? Nothing of the kind happens to males, though. I wonder why ondines even want to get married and have children at all? 
 Redavi are obviously like Moroi royalty, all stuck-up and useless, and completely opposed to learning how to defend themselves against Aquidae, leaving that "privilege" to selkie gardinels and demillir chevaliers. OMG, I'm completely lost in the definitions of all society members. 
 The place is called Lumiere Academy, and is protected with magic wards. 
 There are also many more similarities, but I already got tired of listing them, so I will stop at that.