Wonderful setting, bloat and pacing issues:
First of all, picking up the book after 7 months away from the series felt good. I really love the world that West has created. The characters, the lore, the depth of history. It felt like coming home to someplace both familiar and wondrous. The setting remains a strong point of the series, and this book does a lot to explain and expand the setting and its ancient history. Gods, demigods (the Firstborn of the title), cursed warrior magicians, personified natural forces taking the guise of cats and foxes, bard-born, seer-born, healer-born, regular mortals who are just trying to live their lives. This setting breathes magic and mystery. I love it so much.
The characters are strong. They feel like real people, their motivations are carefully thought out, their reactions feel natural. There are characters who throughout the series have hinted at ancient secrets, and now those secrets are out in the open and coming to call. There are characters whose growth has been a slow roll over 15 books and it is all paying off.
But this book, like much of the rest of the series, suffers from two main flaws: bloat and pacing. They are related, but separate. West has added too many characters, too many threads to follow, too many voices trying to chime in and she struggles to make them all relevant. We are faced with three somewhat different, though essentially similar, old plotting clever men (Jarven, Haval, and Hectore) who get far too much 'page time', often bantering with each other. Meanwhile two powerful characters who have been essential from the beginning of the series (Avandar and Kallandras) are basically invisible and thrown in as after thoughts when used at all, despite being present for most of the scenes. West has grown her cast too large and was not able to effectively wield them all.
Pacing. The book starts off well enough, but often repeats itself. Characters will have the same or similar thoughts over and over. "This character reminds me of another dead character. But she's not! But she sort of is!". Chapters go by where very little happens. Then suddenly crazy important plot stuff. Then nothing for a long time. Then a chapter filled with tertiary characters talking about why they didn't kill each other decades ago. Then crazy plot stuff! Then a long explanation of why the main character feels guilty, like we didn't already realize that her sense of responsibility started in her childhood. Also there were a few chapters where multiple characters decided to start using the phrase 'for the nonce' for some reason, and then they stopped again.
These flaws come down to the same issue: Lack of a good editor. West has repeatedly stated that her editor lets her tell the story she wants. I'm sorry, but the editor is doing her a huge disservice. It's clear West has amazing ability to create worlds, characters and tell an interesting story that leaves you wanting to continue. But she wanders, she gets lost, she tells the same events from multiple POVs, she repeats herself. And I get it, I'm betting most authors do this. But it's the editor's job to fix this. To look at the book and say 'Hey, why is everyone saying 'for the nonce' all of a sudden?' or 'Do you think you could combine these very similar characters?' or 'You spent 6 chapters with these secondary characters not doing much, do you think you could pare it down?' or 'How many intelligent animal ancients do you really need?' or 'Hey, how come the powerful bard and warlord that have been important from the beginning are just standing around doing basically nothing for half the book?'
This series had the potential to be one of the best. But lack of effective editing kept it from being so.
If I was given the role of fixing it, I would turn it from 16 books to 12. 4 books combining Sacred Hunt and House War 1-3. 4 books for Sun Sword 1-6. 4 books for House War 4-8.
That said, I will keep reading. I really want to know how the story ends, how the characters end up, how the world ends up.