I only have a passing familiarity with the Ramayana, but it was an interesting take based on what I know. I saw a lot of comparisons to Circe, but aside from the larger premise (retelling of classic myth from the female "villain"'s point of view), I really didn't get Circe vibes at all.
I think Kaikeyi was a little too perfect and innocent and "can do no wrong" to be super interesting, but that said, I did find myself rooting for her throughout the whole book. I enjoyed reading about the Binding Plane and how she used and grew those powers. And I enjoyed the "women helping women" themes here. But honestly it just made me wish I was reading the Ramayana instead - I wanted to see more of why she was "mistaken" for an evil selfish villain queen because I don't know how that could happen if this were the "true" take (except for the magic of Rom/the gods, which just isn't that interesting).