Two things make this book for me: 1) interesting worldbuilding and 2) oh my god
the female characters. They're everywhere! Doing everything! With, like, complexity! And depth! And differing motivations!
In fact, I think this book fails the reverse Bechdel test (I don't think there are two male characters who have conversations about anything other than the women in this book), and I find the change so unexpected and delightful, I'm beside myself.
Extra bonus of all the women but one (who is the mainest of the three or so main characters but omg not the only woman!) being non-white. There's pretty clear parallels here - Europeans, East Asians, Arabs - and some of the broad, sweeping racial generalizations constructed by the plot of this book (Arabs are the oppressing empire! the Asians are oppressed, downtrodden, and vicious! Europeans are the outsiders/potential saviors!) skirt the line of being dodgy. However, given the work the author has done in pushing women beyond the context of the stereotypical Female Fantasy Novel Tropes, I'm willing to give her the benefit of the doubt to the next book to see how things develop with these various cultures.
All in all, a political intrigue plot driven by strong worldbuilding and an intriguing system of magic and death, with heaps and heaps of female characters doing interesting things.