
Wyvernhail is the fastest paced of these five books. Hai's desperation to save the future from the flames of the unborn Keyi is palpable. She, no overt spoilers, does manage to save everything and tie a neat bow on the whole series. Wyvernhail is also a book of self-discovery for Hai, though I don't think she realizes it until the very end.
I'm not entirely sure how I feel about Wyvernhail personally. On the one hand, I am again frustrated by the way Wyvern's Court is still super segregated, though that is both less and more of an issue in Wyvernhail. I am annoyed by the falcon interference. I am pleased that Hai, despite being pulled this way and that by her magic, is able to have some adult relationships that are implied to be... well... less than healthy. And to be clear, I'm not pleased by the less-than-healthy aspects of this, but by the fact her character isn't infantilized.
Wyvernhail also does a lot of heavy lifting, as far as the World Building for the entire series. There's been bits a pieces of the past scattered throughout the series, but Wyvernhail comes right out and explains what happened with Maeve and Keisha and Alasdair and the falcons. It feels cathartic, but I also doubt Hai really explains any of this to her compatriots, so I'm not sure whether or not it's helpful to the people of Wyvern's Court.
I do like Wyvernhail well enough. Definitely not as up on it as I was on first read, but then, I've grown since then so... yeah.