I stayed up until past 4am to finish this because I simply could not put it down. It's an intense, searing culmination of the suitably epic themes that Amara has been exploring: loyalty, family, tradition, revolution, love. Perhaps fitting then that the final battle sequence seemed to draw on the Iliad for inspiration. It's a bloody conclusion that will leave you exhausted like a good tragedy but hopeful for the new society that will rise from its ashes.
I left off a star because I had some issues with the destiny of one of the characters, but what follows qualifies as a Major Spoiler so be warned. I'm not sure how I feel about Tarek's destiny. I kept waiting for him to be given a role equal with his potential and emphasis in the narrative. Instead he ends up a cautionary tale about misplaced loyalty and wasted potential. I was a little uncomfortable with the fact that he was effectively the only major character from a lower caste in the book, which belies the revolutionary theme somewhat--almost like he's a token, and the saving of the people of his birth ends up being done by Tria characters who've undergone epiphanies. This is old-fashioned in a bad way--like heroic tales of the Civil War about virtuous white people rescuing the poor oppressed slaves. It's possible to read his story as punishment for falling in love outside of his caste, and yet throughout the book he has the same goal of equality as Keshan and in many ways more talent and effectiveness than his fellow MCs. However, unlike them he ends a failure, with nothing left but regrets. I do think Amara did a great job with his characterization and his story is powerful and moving. If he'd been less of a major character or if there had been another lower caste character given as much of a role, I doubt I would have felt this way.
Bottom line: fantasy is my favorite genre, especially M/M, and this is a terrific ride, with genre-worthy themes, amazing characters and world-building, great writing, and one hell of a concluding battle sequence. This is definitely as good or better than most high fantasy novels I've read, whether M/M or not. If you're an addict of the genre like myself, you'd be crazy to miss this.