As sourp4tch clearly stated at the beginning, this is meant to be very difficult without spending gems. However the vily werebeast is actually possible, both as a drop (got one today, yay) and by crafting as we can get plenty cursed fur
My advice will be to forget about the other 3, stop wasting energy on jewelers etc. and focus on upgrading the haunted castle and collecting horse shoes.
And very soon I'm going to take my own advice and store these buildings. Just one more try, wouldn't it be awsome if a werewolf spawned, then dropped a friendly cousin, and then I won a million playing lotto...