This book is something different. Part of me was dismayed when I realized the yugoloths were not part of the OGL, but reading this book I'm actually pretty happy about that.
Daemons, nihilistic self-loathing creatures that hate all life, including themselves, even as they are fascinated by it given their tie to its cessation.
These guys are rather different from yugoloths, instead they are far more fallible and insane. I like this, makes them feel more like creatures of elemental evil given their inability at times to practice restraint.
The book is really well written, and this enough here for you to tone things down or go for really dark campaigns. There many little mysteries and locations as well that one can utilize while designing a campaign.
The art is beautiful and evocative as well...heh, maybe one or two pieces are a little too scary for me! :-)
This was a really interesting book. The gods flesh out a very creative pantheon that ranges between archetypes many are familiar with (the fickle goddess of lust, the heroic knight, the mad god, etc) but each of those is well done.
There are also some interesting gods like the dualistic god of nature and gods that represent the varied stages of civilization and its developments.
I found many of the gods to better represent deific forces much like those of the Greek Pantheon rather than powerful beings with more human mentalities.
If you are looking for a good sampling of premade deities you can't really go wrong with this book.