Heir to the Throne (Sequel To His Servant) C...
Bill and Dipper adopt a boy and raise him until he is old enough to be ready for the throne.
The Prince of Gravity Falls has a lot of growing up to do, being King is one of them. Andrew is a 8 year old boy who was adopted by the King and the servant. Families reunite and new enemies arise.
DISCLAIMER: I don't own Gravity Falls, Dipper, Bill, Mabel and Ford. I own Andrew and the rest.
King and Servant AU is an AU I made up.