When Pinkie's sisters dig up an ancient living weapon designed to fight Discord, they don't know that they have unleashed a massive threat to Equestria. How will the Princesses and the Mane 6 fight a force that keeps growing stronger and which they don't want to harm? After all, how can Pinkie fight a creature with her sister's face? (A sequel to An Earth Pony's Guide to Magic, though probably possible to read without having read the first fic in the series)