Starlight succeeded in her plan for revenge against Twilight Sparkle. She prevented the pivotal sonic rainboom from ever happening, effectively destroying the timeline that lead Twilight on the path to befriending the rest of the Six. Which also kills the three of them. Because Starlight is an idiot blinded by a quest for vengeance. But before Twilight fades away, she tells a slightly younger Princess Celestia and Sunset Shimmer several things they will need to know to have any hopes of keeping Equestria safe from the many countless terrors that await it in the near future.
The story of Celestia and Sunset picking up the pieces of a mirror yet to shatter. Destinies will change. Fates will intertwine. Hearts will break. And forbidden knowledge will eventually come back to bite the Princess in the... Plot adaptation prequel of the original series.
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Tags:
Death: Spike (sad), Starlight (violent), Twilight (eh sorta) but their story counterparts are still alive
Profanity: nothing you won't see on tv
Violence: one particularly brutal scene near the beginning but everything else is pretty mild
Genres:
AU: takes place in universe with with no sonic rainboom
Drama: focus is on the dramatic dynamics of Celestia and Sunset
Sad: melancholic themes concerning main characters throughout
Tragedy: major canon character deaths at the beginning ONLY
Romance: possibly a romantic subplot or two that isn't the main focus
Characters:
Primary: Celestia and Sunset
Secondary: Luna and Twilight/Spike
Tertiary: Rainbow Dash and Starlight Glimmer
Supporting Cast: Pinkie/Rarity/Fluttershy, Wind Rider, The Oranges, Maud Pie, Stormy Flare, Firelight/Stellar Flare/Sunburst