The Escape

It was nearly time.
She pawed at the rocky surface, her jet black hooves striking up bits of moon rock. Her horn, a styled object of nature, filled to the core with the very essence of magic, a beautiful definition of perfection, sent out sparks of violent lilac, which glittered through the thin atmosphere before dying out of existence. Her black-feathered wings spread, tipped with silver in the light of the moon's grace.
Nearly time for her to escape her chilly prison, where nothing existed, except for the shadows that danced in the sparkle of the sun. Of course, she adored the empty environment, where no hope, or happiness, or laughter, could linger. But she'd rather that she, the one and true queen of Equestria, had caused that silence, that destruction of joy and peace, so that the air around her wasn't just empty, but filled with the lovely stenches of death and rage and chaos.
Nearly time for her revenge, to slaughter the current Princess of Equestria. She would mercilessly murder her. It would be a bloody and gory death, and she would scatter Celestia's blood across Equestria, to warn who was truly in charge, to tell of powers so great and mighty, to strike fear and terror into the very souls of her would-be subjects. They would cower in fright as she brought upon eternal night to Equestria. And how the ponies would shriek in horror! How they would bow to her, trembling from head to hoof! How they would shudder and quake in her godly presence!
But she would have to wait. A millennium, imprisoned in this small, pathetic excuse of a planetary object. Ponies often had related her to the moon; simply because her former and extremely feeble consciousness was the ruler of the cursed rock in the night sky, and simply because they were simpletons with no sense of logic. No, she lived not for the moon, but for the distress, and fright, and gloom that was brought along with the night. And the captivity on the pale, lifeless rock brought only more hatred towards everything that frolicked under the sun.
She knew that the moon wasn't just a physical jail cell. Celestia's cursed banishment spell had been threaded with ancient magic, obtained from the very folds of reality. It had sealed her, not only in body, but in mind, spirit and strength too. It had confined her mind; preventing it from plotting, scheming, sprouting dark thoughts that belonged only to the darkness. It had constricted her spirit; no power and no magic were able to channel through her veins. It had wrapped around her strength and extracted it, drawing her consciousness into the rocky plains.
All in all, it had been very dreary and numbing.
However, that timespan had passed in a few eye blinks. Her body had felt no effects from the thousand year confinement, yet she knew it had happened. Her entire existence was intact; but somehow, her subconsciousness had taken the toll.
It was if she had just woken up from a long, long sleep.
As soon as she had awakened, drawing her consciousness back into her, her hatred and rage and chaotic emotions seeping into her heart, her memories flowing into her mind, she yearned to escape. Oh, she knew how; through build-up of ancient magic and the help of heavenly celestial objects she could free herself from the dead prison she had been kept in. But to undo the knots of the magical spell, she would need a particularly strong event and very, very fortunate timing. She didn't have these items of the universe at the control of her hooves, but there was a way out…
The Summer Sun Celebration. The time when the celestial beings crossed her path, and the time when the sun and Equestria formed a solar eclipse.
Previously, the stars, or rather, the ancient souls of Equestrian heroes, refused to aid her escape. But she had planned deviously, and her magic was starting to return to her body. So a little persuasion was all that necessary…
Yes. She could feel it, the shadow magic oozing through her bones, the foreboding glimmer returning to her star-massed mane.
There was a burst of bright light and she felt power coursing through her body, like never before. She lost herself to the immense energy that flowed easily like an electric current, vaguely aware that the chains of Celestia's spell were dissolving…
And with a flash of silver light, Nightmare Moon was free.