Jake yet again said:
You might want some links to Darke's Carnival (e.g. Searching the caravans behind the circus, you find an intriguing letter addressed to Ringmaster Darke. Place a clue token at Darke's Carnival or Ringmaster Darke is trying to recruit new acts from the circus. You may discard an Ally to put the Darke's Blessing condition into play)
I'm not convinced about the" take in a show" ability. $2 will fully heal you at the Asylum. Proximity to the Hospital helps, but $3 for a variable gain is a little too expensive. I'd reduce it to $2 or possibly even $1 for d3 Sanity.
I'm also not sure about Cultists gaining Nightmarish 1. I'd reserve that for really gruesome mosnters. Clowns, for all the horror motifs, don't really fit the "I don't understand how that thing can possibly exist" model, so I'd suggest a Horror (-1) for 1 Sanity (unless worse already) ought to be enough.
Still I love the concept and eagerly await your next work.
The only problem with Darke's is that I didn't want this to require Dunwich.
You're right on the ability - I'll reduce it to 2 - any less though would likely make it too powerful (because of how close it is to the Hospital).
As for Nightmarish, I needed something to be a bit negative, and I really wanted to run with the clown-in-cult idea i had. Do you have any thoughts n some sort of global effect?