For a long time, Equestria has enjoyed peace under Princess Celestia's reign. However, the peace ended when the return of Nightmare Moon sends Equestria into great chaos. In the midst of the confusion, Celestia mysteriously dissappears, and the Mane 6 are eventually banished after a Celestia-approved mission crashes and burns due to Nightmare Moon completely eradicating the Elements, and she finally gets her desire for night eternal.
However, Nightmare Moon didn't count on the consequences and repercussions of eternal night, and, eventually, Equestria begins to get colder, as more and more ponies die out.....
Eventually, a rebel force recruits a lowly theif named Hot Shot, who's past is as mysterious as his reputation, and begins to turn him over to their cause.
After that, the rebel army must recruit more ponies to their cause and initiate...
Operation: Stick N' Move.
I just read what you have of this story. Looks good so far.
Request for the next chapter: Nightmare Moon goes to check on the ponies she banished into the Everfree Forest (Twilight, Rarity, Fluttershy, Applejack and Rainbow Dash). The 5 mares decided that rebelling against Nightmare Moon was wrong of them, and that they'll pledge their loyalty to Nightmare Moon now. Nightmare Moon comes towards them, hearing their conversation, and asks if they learned their lesson. Twilight says they have, and that they hereby pledge their loyalty to her, the other mares agreeing as they all apologize for rebelling in the first place. Pleased by this, Nightmare Moon takes them back with her to the castle. Rainbow Dash becomes a guard, Applejack becomes a baker, Fluttershy becomes an animal carer, Twilight becomes her adviser and student, and Rarity becomes her maid and designer. Pinkie is Nightmare Moon's jester and event planner.
You can continue from there.