The hand-drawn artwork gives the adventure a distinctive style, and the solid, gruesome writing complements it perfectly; the description of the fanatics is pure Appendix N btw!
A couple of suggestions for improving usability at the table:
The artwork is fantastic, but placing it behind the text makes some sections difficult to read. You might consider giving the art a more prominent placement on the page.
The narrative format is engaging, but for quick reference during play, a traditionally keyed map with numbered, separated locations would make the document much easier to parse.
Well done on the interesting adventure!