Before Equestria there was the Empire, ruled by a King and Queen who loved their ponies with all their hearts. The Crystal Heart was the Highest Law in the entire Kingdom, able to denounce any King or Queen and instate a new Prince or Princess who was more worthy of the throne. Very few ponies know the story behind the origins of the heart and, until Prince Sombra stumbles on a old fairytale, no one thinks it is really alive.
Unfortunately She was.
Silken Blade has slept for hundreds of years in her crystal prison, waiting for when somepony would free her and let her fly among the Stars again. Her Curse: She is bound to her Savior til their death.