I hated Mummy: the Curse.
That's not secret; from release onward, I complained about it incessantly. I abhorred the game. I thought it was an unplayable trainwreck of half-baked ideas that was more worldbuilding than roleplaying game.
Book of the Deceived changed my mind.
First things first, the book is /gorgeous/. The art is split between surreal photomanipulations and high-contrast ink character portraits, and both are a cut above what I've come to expect from art in roleplaying game books. Equally stellar is the writing quality; much of the book is just fiction. It reads less like game material and more like translated mythology, complex and arcane and beautiful.
I'll steer away from specifics, but the Deceived of the Lost Guild make compelling antagonists and strong protagonists. The rules within are fresh (if minimal), and the whole package made me want to dive into a Mummy chronicle as soon as I possibly could.
Book of the Deceived represents the new bar for Onyx Path Publishing's supplements, and I eagerly await future releases to see if they can match this work of art.