4.5 stars rounded up to 5. 
 This was a buddy read with Runell. Thank you! I am so glad because if she hadn't offered to buddy read it with me I might have put it off. 
 There are a lot of YA SFF reads out there. This is definitely one of those that's worth picking up. It's set far in the future where people mostly live in space, aboard intergalactic spaceships. Those who live on planets are called Excess, because well, in the future, planet dwellers aren't important. Humans and animals alike are engineered and tailored to suit the needs of the wealthy and powerful. 
 Bring in Nemesis. She's a Diabolic. Diabolics are basically superhuman assassins who will protect their one bonded human at any cost, even their own life. They'll do it happily, because, well, that's all they know how to do. Nemesis's bonded human is Sidonia Impryean, a Senator's daughter. Nemesis isn't treated like a human by anyone but Sidonia, and even Nemesis herself does not think of herself as a human. 
 I won't spoil any of the plot because it's filled with dramatic twists and turns that will keep you guessing until the end. I will say that if you look at the basic structure of the plot, it's pretty typical YA. Nothing incredibly new here. 
 But what makes this story great are the characters. Nemesis's perspective is fresh and interesting, because like I stated above, she doesn't think of herself as human. She has one sole purpose in this world, and that is to protect Sidonia at all costs. Anything else is above her status in life. She has super strength, super speed, super reflexes. She's sort of like a superhero without emotion. She's not evil, but not necessarily good, morally gray. Indifferent to anyone except Sidonia. 
 The writing was excellent, poetic in places but all relatable and easy to digest. There is a romance in the book, which to be honest, I've grown a little sick of lately, but this one is incredibly well done. It isn't filled with needless angst. The characters don't behave like idiots. It's not a case of instalove. And it creates a very interesting dynamic for this cast of characters. The setting was also beautiful and it often reminded me of the movie Passengers. Sprawling spaceships with all sorts of luxuries, anti gravity chambers, salt baths, viewing windows to the stars, indoor rivers and trees, etc. 
 All in all- don't dismiss this as just another YA novel. It was an awesome read that I'd recommend to anyone who enjoys the genre.