I’m deep in the middle of writing the Infestation Tome. It’s taking a while. Here’s what I’m trying to achieve:

1. Players who are grossed out by this stuff aren’t penalised if they don’t pick it.
2. Players who like this stuff aren’t penalised by picking it.
3. You can do interesting stuff in encounters with it.
4. Mortals only get infested consensually, and it’s believable that they’d be cool with this.
5. After they get infested, there’s enough unpredictability and variation that it feels like the creatures have a life of their own.

I think I’ve got a design that’ll work, but there’s a fair bit of writing to go because it’s starting to look a lot like a second seduction track.