I was half asleep when i thought of this and wrote half in that state but it seemed interesting so i went for it. Orphans, Dipper and Mabel Pines may have gained more then they bargained for when the climb up Mt. Ebott to escape their abusive foster family. Now they have a choice. as the 8th and 9th humans to fall down to the Underground they have a choice to be the savior of the monsters or their destroyer. Note i don't own the picture i just tried googling a cool pic that would fit. this was close enough
7 parts