An absolutely stunning book; there's no other way to describe it. The characters and setting are so rich. A lot of times in fantasy, it can feel like pieces of worldbuilding are missing, but there is absolutely no feeling of that in this book. Everything makes sense, even plot twists/revelations that seem to come out of nowhere are actually supported by the text. You'd think these things are the bare minimum to publish a book, but noooooo. 
I loved Jack and Adaira. The shift in their relationships with each other throughout their lives is such a beautiful part of the plot. They have always been and will always be two parts of a whole even if they abhor each other, their actions and feelings are still majorly driven by one another. 
All of the characters experience immense growth, and every facet of their personalities and roles fits so perfectly together. There are various romantic elements, such as new blossoming love, old love being reborn, and older love impacting the foundations of the world as our characters know it. Gorgeous. 
I have a hard time comparing this book to anything else I've ever read. It has a beautiful writing style that is somewhat similar to some Greek retellings I've read, but otherwise, I was unable to draw any parallels between this book and others I had previously read.