King Sombra wasn't killed by the Crystal Heart. He lives on, in the frozen wasteland, returning time and time again to attack the empire. But after one attack, Twilight follows him. Using his skills of manipulation, he plans to use her to retake the Crystal Empire. But even if he can be stopped, he has another plan waiting to be set into motion. A far more dangerous one.

One night, a strange filly mysteriously appears at Twilight Sparkle's door. Finding her, Twilight takes her in, just for the night, but quickly develops a bond with her.
However, a stallion with an obsession towards the filly arrives in Ponyville when she does. Twilight and her friends will have to figure out what he wants, and why they're in Ponyville in the first place.

Five years after Princess Luna left and formed the New Lunar Republic, the Republic has become caught in a war with the Solar Empire. After making a comeback, the Republic decides to try the impossible and convince the Mane 6. But even if they can, it's still a longshot that they can win the war.
The Solar Empire is no longer controlled by Celestia. Her lords took control after seeing a weakness, and have caused terror and death throughout the world in Celestia's name.
Celestia, meanwhile, has created the army within the army, Celestia's Army. However, a strange obsession prevents her from acting against the Empire.