Nightmare Moon.
True Queen of Equestria. Ruler of an eternal night.
But once upon a time Nightmare Moon had been Nyx. A small filly, who was loved by Twilight Sparkle and the Cutiemark Cursaders. That filly is still in here. And due to it Nightmare lies in conflict with herself.

AN: This monologue is a tribute to Pen Stroke's awesome story Past Sins, where Nyx is the main character.
Inspiration songs: (spoiler alert!) Past Sins by The Snatcher and Who I am by The L-Train (Cover Doc Dycer)