Sacred Throne is a pretty good trilogy, with themes I love, a somewhat clumsy plot in the second and third installments, and competent writing throughout. It's a solid B, or something like that.
The first book is the best, for the subversion of several tropes. Spoilers, but: The young lesbian female protagonist we find to be opposed to the corrupt authoritarian cruel religion, in the best YA tropes. The religious figures say doing magic calls demons from the netherworld; we are eventually lead to believe that this is a lie. But then, towards the end of the novel, we find out that the religion was actually correct, at least about the demon-calling thing, and battle ensues.
She finds herself somewhere between Martin Luther and Joan of Arc by the end of the first and in the second novel, although the novels very much characterize her as making relatively few choices. By the end of the trilogy, well, she discovers that God is dead, which I cannot help but like, and she also has a romantic partner, as is inevitable, but the path there feels like there's a little too much deus-ex-machina involved. Overall though, I enjoyed it. Don't go there searching for enormous sophistication and fine emotional details, though.