Starlight Glimmer asks a question of Twilight: If Rainbow Dash had never done the sonic rainboom, would Equestria be better or worse than it is now, on the whole? Twilight, always interested in the hypothetical, agrees to find out.

This is essentially a write-up of the Season 5 finale, inspired by its animatic, as I was deeply inspired by it. Given that the season is on hiatus, I decided to do the unthinkable and actually write a serious pony fic. There will be spoilers from the animatic.
I hope you enjoy this fanfic! Rated T for caution, would rate E10+ if I could. I doubt anything T will happen, but it might get a bit bleak in some later chapters.
Pre-reading by someone who asked me to refer to them as TidepoolSW, as well as the excellent DragonDance, which I am very grateful for. Edited by a wonderful user who wishes to remain anonymous. Thank you very much!

On a dark night filled with even darker magics, an insane cult attempts to give Nightmare Moon a body and life of her own, utterly separate from Princess Luna. But, when the spell is interrupted by Celestia, something unexpected is created.

Now, a little black alicorn filly named Nyx finds herself living under the care of Twilight Sparkle, only to be haunted by memories and emotions from her past. Is she Nightmare Moon reborn or is she simply a doppelganger with a soul and mind of her own? Can Twilight Sparkle protect Nyx from those who refuse to see past her dragon eyes and black coat?

Or, will Nyx be forced to inherit the sins that may not even be hers and become the greatest evil Equestria has ever known?