This was such a good book. I thought the world was so interesting and different. It took me a little while to understand the differences between each group of people and I even I had to start the first like half hour of the book over so I could make sure I was getting it all, including the POV shifts, but once I understood it, it was such a good read.
I really liked the world building in this book. The three separate blood types making a caste system was intriguing. I really enjoyed that the book played heavily with the fact that you truly don't know someone's blood color just by looking at them so there were many who were able to pretend to be in one caste over the other and as long as they never got an open wound, they would essentially be able to masquerade for as long as they wanted.
I also liked the idea of the blood magic they had

though one of my very first questions was why only the red blood people could do it which ended up being one of the big reveals at the end - in actuality, anyone can do it. I figured this would be the case but I still enjoyed the reveal and how it connected in a way to our real-world history of colonization.

This book has so many obvious parallels to our current world and political climate and that was no accident. It's amazing how much the author was able to fit in this world to make it so similar to ours but so different at the same time. 
I also really liked the portrayal of addiction throughout this book. It was great to see how realistic it was and how Sylah was still dealing with the withdrawal effects even 5 months after quitting cold-turkey. I liked that it wasn't just forgotten about and dropped in the middle like it easily could have been. It was very much routinely brought up and focused on which is a very real issue that addicts deal with. I loved seeing that representation and I hope it continues throughout the series.
Finally, I loved seeing these characters grow throughout this book. Syla goes from being completely hopeless and giving up on herself and the empire, to being inspired and passionate and full of determination to fix the systemic issues within their country and helping the ones who are being oppressed. And Anoor goes from being a very naive and kind of spoiled rich girl to having her eyes opened to how other people are being treated in the government that she was benefitting from and being determined to change it and help them. I hope they both continue to grow and find their own power as the series progresses.
I can't wait to finish reading this series. Unfortunately, I didn't realize that my library doesn't have the other two books so I don't currently have access to the rest of the series. It might be a while before I can finish it.