I thought the book was pretty good. I loved the world building and the History of the past wars. But I didn't really care about any of the characters. Rin drove me nuts, I felt like she rushed into a lot of things, without thinking things through first. I know people would say its because she's young. But I don't think that was the case, at least for things she does later in the book.
I really didn't like Altan either, and I wonder why Rin acted the way she did around him. There are a lot of trigger Warnings in this book, rape, torture, self harm, to name a few.
I did like it enough that I do want to read the next one, that comes out in August. Especially after how the book ended.
I would recommend this book, but look into all the other trigger warnings, that I didn't mention above, because there's definitely a lot more than what I did list.