R.F. Kuang's debut won quite a few awards and deservedly made her a name much discussed. This is the first of her works that I've looked at, and was really looking forward to it. It's great to have a new voice, one with a background, writing about a world, quite different to the default medieval Western one.
The settings has the general roughness you'd expect from a medieval-ish fantasy. The characters are generally well drawn and the world has a range of interesting aspects to it that are gradually unfolded over the course of the book. Underneath it all, slowly rising to the surface, is a history of prejudice, injustice, deceit and violence that becomes evermore grim and overwhelming.
By the end, I personally found it a bit much, and here the spoilers kick in. While we can somewhat understand the main character, Rin's, journey, it is ultimately one of almost continuous violence, defeat, and destruction, culminating in her engaging in acts almost as evil and depraved as those on whom she seeks revenge.
Having dug in and bent the world to her will in the first half of the book, during which she overcomes the various obstacles put in her way, in the second half she is borne along by events, with no agency, a constant victim, as the world tears itself apart around her. She repays it by tearing it apart much worse (as do the squad of others she ends up with).
Generally well told, it feels unnecessarily grim to me - that's probably just a taste thing. There are important tales to be told about how humanity gets crushed by the violence of injustice. I think Octavia Butler or N.K. Jemisin might have clearer voices on that, but for Kuang to be working her way toward that kind of thing, particularly as young as she was writing this, is damned impressive.
The writing style got me by times. This is a quasi-medieval setting, but terms like 'genetics', 'cognitive dissonance', and 'suspended animation' get bandied around as though perfectly natural. They use hypodermic needles, and heroin, but refer to volcanoes as 'fire mountains' (which nonetheless spew 'volcanic gas'). These should just be trifling frustrations, but were just a little to frequent and kept knocking me out of the story, which is a shame.
So, glad I read this one, but I'm not too interested in reading the follow up. These are not pleasant characters, and I don't really wish them well, however much I sympathise with what has happened to them.