Rainbow Dash's rainboom never happened, so the elements of harmony were never found... and their holders never met. Without the elements of harmony to protect Equestria, a battle against a powerful foe was inevitable. With King Sombra's return, he enslaved his subjects and turned them into his own soldiers. With an army to back him up, Sombra declared war against Equestria. Now, every pony must pitch in to help the cause, and give it all they got to defeat Sombra before all of Equestria falls under his evil reign.