While researching cutie marks at Twilight Sparkle's library, the Crusaders find an ancient book of spells hidden in the floor. Naturally they open it.
Possessed by the dark magic of the book, the Crusaders use everything they've learned about the Mane Six over the course of the series to be surprisingly effective villains. The Mane Six and the Princesses meanwhile have some trouble adjusting to the idea of the Crusaders as dangerous enemies. What follows is a dark comedy.
This Fan Fic contains examples of:
- Affably Evil: The possessed Crusaders just want to be left alone to complete their ritual. They can't understand why everypony is being so unreasonable about stopping them.
- Batman Gambit: The CMC figure that, once they have summoned the powers of darkness and gotten their cutie marks, the Mane Six and the Princesses will throw the evil back in its can like they always do. They later change their minds about destroying the world, and by the time the summoning is complete, most of the "heroines" are petrified.
- The Bad Guy Wins: Oops.
- Bilingual Bonus: The requisite Ominous Latin Chanting is in Latin. Google Translate exists. Do the math.
- Black Magic: Now, really, who'd of thought an evil book of spells had evil magic?
- Blood Magic: Required by the summoning ritual.
- Demonic Possession: Just opening the book is enough to turn the Cutie Mark Crusaders into willing servants of evil; fully prepared to bring hordes of undead down on Equestria and use Spike as a blood sacrifice.
- Downer Ending: The Ancient Ones are awakened, and they destroy the clubhouse with the Mane Six and Crusaders inside.
- The End of the World as We Know It: The ultimate result if the ancient ones actually get summoned.
- Evil Versus Oblivion: Discord and Nightmare Moon turn on the Crusaders for this reason.
- Exact Words: The book promises great rewards for its users. It never says they'll get to keep those rewards.
- Evil Is Not a Toy: Everypony else is desperately trying to convince the CMC of this. They learn the lesson too late.
- "Freaky Friday" Flip: Discord inflicts this on the Mane Six. Then their memories switch as well. It sticks.
- From Bad to Worse: The book transforms the CMC into alicorns. Then they awaken Nightmare Moon and Discord.
- Greater-Scope Villain: The Ancient Ones responsible for enchanting the book remain vaguely defined forces while the corrupted CMC drive the action. They appear and are even given names at the end, taking over from the CMC as the Final Bosses, but they also refer to a "leader" who is never explained.
- Ominous Latin Chanting: See Bilingual Bonus.
- Pragmatic Villainy: Discord and Nightmare Moon are aghast to discover the Crusaders are quite serious about summoning the ancient ones to destroy the world.
- Shoot the Shaggy Dog: The CMC successfully complete the summoning in spite of everypony else's efforts, and the remaining heroines and the CMC die ineffectually.
- Tome of Eldritch Lore: What kicks off the plot and is the source of the conflict.
- Theseus' Ship Paradox: Brought up by Discord (or rather, the axe variant), prior to inforcing a "Freaky Friday" Flip on the Mane Six.