Onyx is a young crystal pony with a twisted mind. Starswirl the Bearded whisked him away from his home with promises of being his apprentice. Sombra is a strange creature who never wanted to be remembered. However, we don't always get what we want...
After years among the three pony tribes the Two Sisters fight their first great foe by themselves: King Sombra, the tyrant King of the Crystal Empire. Nothing goes as planned, everything, and everypony are not as they seem.