This is a my little pony fan-fiction, I have made many OC's but i do not own MLP or Hasbro. (On hold at the moment)

This is a my little pony fan-fiction i do not own MLP or Hasbro only my OC's and their designs. One night when Rainbow Dash is up late she spots a shadowy figure emerging from the dark layer of clouds above clouds-dale, could it be a infamous Night Mare or is history about to repeat itself?