This is a continuation of some thoughts I've seen concerning the incongruity of Wake of the Watcher. Actually, it's two continuations of this, only I used the more interesting one as the title. I don't know if it will do any better, but I thought I'd throw them out here for criticism, and add whatever development I may as it occurs.
The first thing I should say is that I'm planning to have the Crooked Kin along, or incorporated in some way, throughout the AP. Secondly, I think it may be viable to open up a few sandboxy options after Lepidstadt - give the party three or four trails to follow and let them choose. If they end up in Feldgrau, fine - if not, it will keep. I think.
So then, here are two possible events, which I haven't even begun to really flesh out or incorporate yet, but here they are nevertheless:
Dark Fey - a nice, disturbing faery tale, inspired largely by Susanna Clarke. There is a brief sequence in her novel (Jonathan Strange and Mr. Norrell) in which a lonely road leads to a single guardian who stands before a grove of decidedly uncommon trees which surround a castle or manor estate of some sort. It plays up some of the more grim aspects of Grimm, among others, and I'd certainly be pulling in a bit of Gaiman as well.
Evocation Day - This autumnal holiday of Nethys would, I think, take on a very Halloween-faire feel in Ustalav. Also a touch of Pharasma which it might not have in other places, and maybe some fort of Danse Macabre rites. I don't know what else, honestly, except that the Kin could really play an integral part here, and I have this image of a sort of open-field dungeon, with lots of mirrors and people in masks and things not being what they seem.
These two notions could be parts of one WotW replacement, or separate events between other parts of the path - whether or not WotW is included, actually. Er, thoughts?
Your Evocation Day idea sounds amazing, and I would love to hear you expound upon it. Sounds like a wonderful mix of game types (ie interaction, exploration, & combat). Where were you thinking of setting it?
Perhaps at the fields and holdings of a deposed noble lord of Veiland? This lets you have a "ruins" aspect to the social event, and the sorts of things that the PCs dig up could have political implications (as they are relatively "new" ruins, Veiland only having thrown off noble rule a decade ago). I'm imagining most of the goings-on happen in the bailey of a castle, with some sort of strange hide-and-go-seek event out in an overgrown crop field.
(Excellent place to have Adivion show up, if you're in to that sort of thing.)
Ooh, hrm...the Vieland estate idea would support a sort of hedge maze setting, as well. Another thought I had was that, being Ustalav, they hold their Evocation Day faires in graveyards. Which might very well be some of the safest bits of open land around. Most of the time. A sort of sprawling Highgate setting could be interesting, though.
Bringing me back to the estate/hedge maze notion...mirror traps! Will Save vs. trapped in mirror, and/or all manner of interesting illusions.
Given the holy symbol of Nethys, I thought that Neth-masks might be common, as well. I'd love for the characters to have no idea who's on their side, or where they went, or perhaps even to lose one another in the place.
Hrm...