If I was not going to run games in Duskwall, I would run them in Setine. This is a setting for the World Between that benefits from borrowing from several great sources, remixed in my own fashion. I think you can see how ideal it would be for this game. Anyway, take a look if you like.
https://fictivefantasies.wordpress.com/2012/08/28/setine-the-white-rose/
https://fictivefantasies.wordpress.com/2012/08/28/setine-the-white-rose
I thought that sounded like Paul Hughes’ map. Cool idea! Paul’s stuff is great.
I also set it in Jack Shear’s world, the World Between. I think the most innovative thing I did here was play with the timeline.
In Paul’s version, the city was once beautiful, but was now submerged in undeath. You could play in Setine’s heyday, or its modern grimness.
I took it a step further and reclaimed the city, so you have both the heyday and the undead occupation in the past. That leaves delightful areas like the Rubble District (formerly the Silver District) and the Baths.
That also makes this setting a good fit with the rules as written for Blades in the Dark. You can bring in whispers and keep that undead theme and it fits in smoothly. You have fallen nobles, wealthy merchants, brutal thugs, and all manner of scoundrels. You could consider this a 16 page source book city. =) You don’t even need all that; for regular play, just the pages with the neighborhood descriptions and a map will do.