Billdip au

This is centered around the idea of reincarnation, namely for Dipper. The idea was that around the 16th century, Mason(Dipper), William(Bill), Willum(Will), and Killian(Kill) all lived in the same house, though Mason lives as a servant. When Mason dies, Bill does black magic to bring him back, effectively turning everyone in the house into demons, but trapping Mason in an endless loop of reincarnation, unless he can remember his true self.