First off, in the interest of full-disclosure, I did have a (very small) roll in bringing this book to fruition, as the Onyx Path open development process allows for varying degrees of involvement from folks who are not writers or artists or developers of a title. Second, know that the book I helped create (again, in a tiny way) is wonderful.
In contrast to some earlier books on the subject of vampire magic that we've seen, Rites of the Blood aims more toward an exploration of the various schools and practitioners blood magic rather than being a "book of spells" and rules. Oh, do not worry, for there are PLENTY of spells and rules in there. There are also many questions asked, crazy and surprising mysteries presented, along with all sorts of new takes on what blood magic is and is not.
Now, one may well ask: Do we REALLY need more Thaumaturgy in this game? The answer is a resounding: It depends on what you want in your game. Sure, it seems like every Kindred, Cainite, and their sires have access to some kind of magic, be it Tremere-Brand Thaumaturgy, creepy Koldunic rites, Necromancy, Assamite, Setite, or Anarch Sorceries (oh my!), but if you want to use any-or-all of these in a game, this book will help you do so while bringing some of the spooky back to these practices.
[5 of 5 Stars!]