Gravity Falls is really heating up, and thanks to the "The Last Mablecorn" I have a pretty good idea of what's coming.
In "The Last Mablecorn", Stanford was able to protect the Mystery Shack from Bill. Now though it seems like Bill plans on taking over someone else to get to the Pines family. I have gone through it over and over in my head, and I've come to only one conclusion. Bill Cipher plans on possessing......
That's right, it's Soos. Soos is the most obvious choice because he works at the mystery shack so he has unrestricted access to the shack. He also lives away from the shack so Bill can get to him. Now your probably wondering "Hey, what about Wendy. She fits the bill to!" (See what I did there) Yes, I have thought about her being the target, but Stan trusts Soos far more than Wendy. So it seems much more likely that it will be Soos. I hope I'm wrong,but we all know what Bill is capable of
I also have a theory about the season 2 finale....I think that it will end with Bill winning, and season 3 will be about a rebellion to save the Earth. Either way things are not looking to good for Gravity Falls future.