After the Changeling invasion and discovery of a new and powerful type of magic Equestria fell into a violent and bloody civil war leading to the rise of a militaristic superpower. But one day it was enveloped in a deep fog, and no one left. Those who went in never returned until one day as the fog slowly crept beyond Equestrias borders a pony emerged, who spoke of demons, and of the power of their souls.

He spoke of Demon souls and the threat they posed to the world. stealing souls and driving them into psychopathic murderous frenzy making them a threat to all those still sane.

Gilda now enters the fog as a criminal in search of her old friend Rainbow dash after being cast out for thievery. Have the demons found a new slave, or has Equestria found a hero.

Demon souls/MLP crossover
Set post Canterlot wedding and Return of the crystal empire but before Twilicorn.