Hasbro's Persistence

When a mysterious cult kidnaps Button Mash and takes him to a mysterious island to be sacrificed, the Mane Six, along with four stowaways, set out to save him and find out why he of all ponies was targeted. However, the reasons behind this may bigger and more malicious than anything the ponies could ever imagine. Title references "Hades Persistence" from Beyblade Metal Fury.