Rainbow Dash hides in her cloud fortress hidden from the enemy below. She remembers back to when Equestria fell along with it, her five best friends and others too.
Dicord has escaped from his mental prison and his armies of traitors, mutants and dragons are attempting to siege Canterlot.
Luna hates Discord for what he is doing to the land, but neither Luna or the dying Celestia can harm him. Only Nightmare moon was ever that strong...