It irked me more in this book just how convenient the magic often is, and how poorly described. All we really know is that it's intent that matters, not form, but that Kurtz spends a lot of her time describing ceremony. Most of that ceremony is both religious and very similar - that is, the interesting warding cubes that in the original trilogy were so interesting still play a role - the same one. We get minor hints that they're capable of more, but somehow those different forms look just like the original. But while some acts - like warding - require careful ceremony, other, more complex acts, can be activated just by touch - or by nothing at all. There's a great deal of inconsistency. Some things just don't make sense.
We hear mention of Ancient Ones and of a group called the Airsid, but no useful detail. The further Kurtz takes the magic, the more clear it becomes that there is no underlying system. My guess is that she made it up as she went along originally. That worked well then, but as she dug deeper into the world, she didn't spend the effort on magic that she did on religion. It all adds up to dissatisfaction, since a number of plot points turn on the viability of magic, but there's no way to predict its success or failure. Haldane access to magic is not explained either.
The moral ambiguity of the prior books in this trilogy continues. They literally say, at one point, that it's important to let Cinhil believe he's in charge. King Cinhil, mind you. And Camber et al feel free to give orders (e.g. rounding up some Deryni) despite having no authority to do so. They're comfortable completely disrupting and redirecting the lives of others (humans especially) for their own convenience, and in service of what they believe to be important. Only their intimates seem to be exempt from these interventions. They complain when Cinhil makes a small decision of his own - about his own children - that makes their own deceptions harder. In short, they act just like the Deryni stereotype they're trying to fight. For example, they complain that the court has moved from a 50:50 human:Deryni ratio to one that favors humans - despite the fact that Deryni seem to be a fairly small minority in Gwynned.
The problems with magic and morals combine in this volume. While the Deryni take a free hand changing the minds and memories of low-ranked people whenever it strikes them, they're powerless to act against a handful of genocidal bigots. Why is it that those minds can't be controlled just as easily as those of underlings? Only once does anyone really speak up against this manipulation, and is then easily closed down. I'd like to believe that Kurtz was deliberately writing a novel about a sinister, Machiavellian crew, from their own point of view, but it's all too clear that we're meant to believe in the Deryni cause, and to excuse their means in favor of the ends they aim for. I couldn't do it.
The book takes a sudden turn toward brutality toward the end; a change from the somewhat sanitized violence of previous books.
In short, this trilogy disappointed me. Where I expected an exploration of Deryni magic, I got ecclesiastical habderdashery, and a morality that was not so much ambiguous as straight-out repellent. Far from rooting for persecuted Deryni, I came away thinking that none of the sides was particularly attractive. If you want your Deryni a little less goody-goody, this is the book for you.