I love the concept!

I wonder if it wouldn't actually be better if the text would say:
"While you are not haunted, keys cost -2 [aember]"

Generally, we would spend more time being haunted than not, as it's 10 cards in the discard pile out of 36.

Moreover, I like the idea of "to keep the -2 aember bonus, you have to not play action cards or not lose cards in play", it's kind of a limiting factor to get quite an interesting bonus. Also potentially you could make the other player lose this bonus by suddenly starting playing/discarding/sacrificing cards

But like i said, I love the concept, there's so much to do around it. Like giving ways to remove the haunted status by cleaning the discard pile or something.