It's a fantasy book. (Sorry this is a little late, and FYI my answer contains spoilers)
Explanation:
The series is written by Sabaa Tahir and is a fantasy book. There is quite a bit of a romance within the book and a lot of violence. The main characters are Laia of Serra, The Blood Shrike (Helene Aquilla), and Elias Veturias.
Book one introduces all three characters. They are being trained under Keris Veturias, (The Commandant) Elias's mother and a brutal woman who kills anyone who gets in her way. Laia of Serra must try and find a way to escape.
Book two in the series is about the 'aftermath' of Laia and Elias. During this book, old characters are reintroduced. During the second book, The Blood Shrike is still obsessed with finding Elias. The main antagonist is Keris Veturias.
Book three in the series introduces The Nightbringer and his devastating past. He becomes the main antagonist. By now, Elias has been named Soul Catcher and has to leave all that he loves behind. Although Laia continues to hold on to him, she must leave him aside to secure a treaty with The Blood Shrike.
Book four was probably the saddest one. During this, Elias is basically torn between being Soul Catcher and being who he wishes; Elias Veturias. Laia is still commited to trying to release him from his position as Soul Catcher. During this time, The Blood Shrike also is frantically protecting her sister Livia (The Empress Regent) and her nephew, Zacharias, (The Emperor) at all costs. After all, they are the only family she has left. The Nightbringer seeks to release all jinn unto the world and to kill everyone. Laia and her allies must find a way to stop this from happening. The Blood Shrike finally has found a lover, and it has made her more vulnerable to the world now that she loves. At the end of the book, there is a final battle. Warning: The ending is pretty sad.
I think the book series is pretty good, but be mindful it contains a lot of violence.
(Just a heads up, I didn't copy and paste this)
