BillDip: Pine Tree's Deal

It's been eight years since Dipper and Mabel defeated Bill.
The twins have just returned to Gravity Falls after their parents died in a horrifying accident, and they find their Great-Uncle Stan on his deathbed. Mabel is one death away from an irrevocable spiral into depression, and what Dipper is willing to pay to prevent that? The steep cost of making a deal with the devil himself.
This is an RP that me and my friend Simon (depressiveblook on Wattpad) are doing. Updates may be slow as a result. Please comment what you like!
Bill is written by Simon
Dipper is written by me