In the alternate hellish Equestria, Midnight and friends failed to purify the Pillars of Obscenity, being once the Elements of Harmony and became their servants.

In the human world, Sara, sister of a ill corporate CEO started a bank robbery and got killed and betrayed by one of his companions. Her souls was put in that hellish Equestria, were she was met and tortured by the Pillars. This, until a rust scaled man leaded Sara to a pair of hellish gauntlets and gave them to her, resulting her to become a vile humanoid pony that the man baptized as the Satanister.

Her new mission was to return to the real world, but first she has to beat the pillars and kill the traitors in the human world. The vengeance can be served cold.