"[Count Dracula had] an enormous penis, which on holidays he tied to a chaffinch and let the bird carry for him on the long silk thread as it flew ahead"

Dream hunters, who follow the same figure from the dreams of one person to the next, until the terminal loop of two people dreaming of each other is achieved, or, if it isn't, until they can compile a hagiography of the dreamed figure across different people's imaginations (iirc these weren't two separate possibilities for the dream hunters--either one is true, or the other one is, depending on which account you believe). Their scripture is a dictionary about themselves compiled by others (this book)

A book written in poison ink so the reader dies if she reads too quickly, passed down as an heirloom with each generation dividing it in two again (also this book)

The fake Khazars, or the Khazar's doubles, who would sometimes speak the Khazar language, but only for the lifetime of a strand of hair (apparently 3-4 years), and could lose the ability in the middle of a sentence. One of them had all the important information about the Khazars tattooed on his body aka "the great parchment" (not confirmed the be this book, but I would assume)

Maybe every third character turns out to be satan, which really vindicates my 95 year old catholic grandma

2/3 of the way through reading this I had to travel and downloaded an ebook of it, and I was thrilled to find that it is meticulously hyperlinked. One of the rare pre-ebook books for which reading a digital copy provides a really new and interesting experience, not just convenience

"one of those journeys were every step is a letter, every path a sentence, and every stop a number in a large book" ahh right one of those