With that being said, this book mostly feels like set up. Where the first three books definitely lead into one another they are still each a solid narrative that has a satisfying ending. They just have a tease of what's to come next. The Blood Mirror feels like half a book that just ends. It's a good half of a book but it doesn't have the typical arc I was expecting.
I kind of wish that I had waited for the last book to come out and then read these last two together. It seems like that's how they are intended to be. They're definitely one story split between two books where the earlier ones felt like complete stories told in a series.
I did like the book though. It made me very excited for the next book and to read the conclusion of the series, whenever that comes out. I just hope the wait isn't too long.