The Dazzlings have won. The Rainbooms failed and the sirens have regained their true forms. The world is theirs, but first they have to make sure that it remains that way...
All they really wanted, was to be adored. Then comes the friends and ruined it all, leaving them weak and next to mute. Only it is not the end to the train of woes, but where will they eventually end up? Only Pinkie Pie may know that.
Of course Rainbow Dash had to start a band with her friends in time for the Battle of the band, where they crushed the Dazzlings. If all they actually wanted; to be adored, why not help them in a different way? Their gems are dead.