Lunar apocalypse
One exceptionally dark and gloomy nightmare night some little phillies were out galloping around, forgetting to bring the candy offering to nightmare moon, ever since she came back to her old self. One weak pony wished she had the respect that was given to princess Luna. She didn't care what it was from whether it was fear or admiration, she just wished she had it.
Gazing upon the statue she said "I wish I could force everybody to love me." she was always one to feel left out. "I'm going to do whatever it takes to get to the very top, where I can be loved and cast away anypony who doesn't!"
This little Philly was named Luna after the split between princesses. She devoted years of her life to studying magic and figured the best way to gain love and respect, for this pony was born with a dark heart, was to take over equestria with any force necessary. She found upon her research the alicorn amulet and realized it was still in existence after twilights duel.
"I've got to find that amulet then my spells can take full effect and all of equestria shall be mine." After her long extensive search for the amulet it was finally In her grasps. "Now that I have this no spell is impossible to master, now where is that book" she uses her first spell to float the book to her. "wow my magic could barely lift a feather before. What a great feeling of absolute power!" after about a minute of searching she exclaims "I found it, I found it!!" in a sing-song voice. "Now let's see what new magic power can really do."
she trots quickly to the graveyard eager to try out her spell. She chants "rise from the darkness only to obey, reach out from the graves and see the light of day" suddenly her horn shoots a single bolt and she wonders "that's it?? Why didn't it work?"
*crunch* a rotten hoof punches through the earth. then another and another until full ponies start to come out and walk once more. "good, my reanimation spell was a complete success! Now let's see what all of equestria thinks of me now." *pointing to canterlot castle off in the distance* "go my minions storm the castle kill anypony who gets In your way!" she proceeds to cast a levitation spell to spare her from walking and follows her undead army.
She walks into the castle to a blood bath of royal guards. She spots Celestia's body at the base of the throne. Smiling at the sight of her new kingdom she says, "ah my loyal subjects have killed the princess. I do believe this makes me the new princess Luna!" she laughs with delight casually brushing Celestia's corpse aside. "what a beautiful castle, fit for my ruling." what she didn't realize was that one guard slipped away, bloody and wounded. He rushed off for help from the only pony he knew could save them, the original princess Luna!
For days her tyranny remains intact, to her she has no equal, but today was a good day for her. She had a first class ticket heading for the crystal empire. Her army was already mobilized, but they're moving extremely slow. When she walked out of the castle she yelled, "where are all my loyal and loving subjects? There is nopony to wish me luck upon my departure." They, of course, were hiding from her because she has already slaughtered any protesters of her power.
At precisely 1 o' clock she boarded the train, which she demanded to be empty for this occasion. She sits back and daydreams about the crystal ponies being her loving and adoring subjects. "this is what I always dreamed of. Everypony loves me and respects me, what more could a princess like me wish for?" Right then she heard a thump on the roof of the train. "why, that sounded like a carriage landing upon my train. What fool would dare challenge me? I am the most powerful out of everypony!"
Using her magic to rip the roof opens the original princess Luna lands her hooves on the train. "Luna, your rain of terror has to end, there can be only one princess Luna and I had this title way before you!" the new princess replies "haven't you felt what it's like to be an outcast? I'm staying the princess unless you can rip that title from me!" Princess Luna fires a single bolt clipping the new princess' horn. The new princess looks in disgust and exclaims "why would you do that? I just had it polished!" she fires bolt after bolt of magic at Luna but it's deflected by her magical spell ward.
They continue firing magic at eachother backing up to the roof of the train. The new princess realizes that they are evenly matched. "you should give up now you old hag, you're magic is merely equal to mine, but I'm just getting started!" with that princess Luna jumps off the train and gracefully lands on her hooves, leaving the new princess to feel victorious. "I really beat Luna, the strongest princess there is!" the new princess screeched.
Her celebrating was cut short when she turned around to a low bridge. She hit with a splat and was immediately killed. The tyrannical princess was no longer a threat and her reanimation spell decayed and the army turned to dust. Princess Luna cleaned up canterlot, restored order and peace, and succeeded her sister to the throne. Only one thing was left to do, and that was to make sure nopony felt left out again.