Den is a Vampires & Claymores supplement that supplies GMs with a host of tables for quick story element generation.
The PDF is 16 pages, with really solid backgrounds and a consistent, atmospheric aesthetic. The fonts feel a bit plain, but everything is clear and easy to read.
The overall tone is towards grisly gothic B-movie violence, however there are some factions towards the end that break the mold, and there's a nice little triangle of conflict between the Hunters, the Order Of The Dragon, and the Sang.
Overall, if you're looking for some quick set-dressing for your vampire game, so long as your tone leans a bit lurid, this is definitely a solid resource. It's built for Vampires & Claymores, but it seems perfectly useable for other systems as well---so long as those systems feature vampires in the modern day.