There were some aspects of this Beauty and the Beast reworking I found really interesting — mostly, the Greek mythology that was mixed in. It didn’t feel like a typical woodsy-castle-y faux-medieval-y setting, which was refreshing, and the references to the Kindly Ones — aka the Furies — worked pretty well for me. The complex relationship between Nyx and her sister was actually kind of interesting too; it’s not straightforward, because everything is not as it first appears, and neither of them are honest to each other.
But otherwise, there were a lot of aspects of this I just couldn’t get into. Both the relationships the main character had just felt off, despite the attempt to show a dichotomy between the two where one, to borrow Tolkien’s phrasing, ‘looks foul and feels fair’ and vice versa (except mostly acts/feels; they’re both handsome, as I recall). The romance tends to the insta-love trope, and given that Ignifex never makes himself really pleasant (unlike, say, T. Kingfisher’s Beast in Bryony and Roses).
There are some interesting aspects, as I said, but looking back at it as I write this somewhat belated review, it definitely never came together for me, and it didn’t really become memorable either.