Sombra had not been defeated by the cristal heart and he managed to conquer the Crystal Empire and then all Equestria, having almost all his enemies as his slaves. But there's only one pony who had not bowed to his will and status: a white alicorn princess that once was the loved ruler of Equestria. Sombra, however, want her more than anything. He wants her to be his most faithful slave and he want use everything to do so, nor that he has to use more obscene methods.