The princesses gave their magic to Twilight to prevent Tirek from stealing it. As a result, they end up stuck in Tartarus. The fact that things manage to go downhill here says a lot about the wonders of family.
With her new apprenticeship under Nightmare Moon, Empress of Equestria and Queen of the Eternal Night, the orphan filly Twilight Sparkle plunges head-first into the conspiracies, secrets and intrigues of the Empire.
Celestia decides to attempt to reform Discord, so she taps a pony with a similar background for the job. ("Keep Calm and Flutter On" as it occurs in the Petriculture AU.)
Each night I’m trapped in the dark, immobilized. I hear whispers as they operate on me: they say I shouldn’t be alive. Twilight refuses to tell me about the operation. Sometimes she can’t look me in the eye. What did they do to me?
2022 Rewrite in Progress... The wreckage of Forward Unto Dawn lands in Equestria. Separated from Cortana, John is forced to deal with the consequences.
An Elite Ultra and his squad are stranded in Equestria. How do they get back to the Blessed Path? Do they want to, when a symbol of their religion tells them otherwise?