Luna didn't become Nightmare Moon on her own... something external changed her. But not only her.
Thanks to @anonsheepdog154 and @stunthead for their help with this project, and their patience despite my straggling!
Vector graphic artwork:
@stunthead
@anonsheepdog154
https://www.deviantart.com/cayfie/art/Lord-Tirek-469103579
https://www.deviantart.com/herrmyrddin/art/My-little-Pony-Windigo-Vector-295073681
https://www.deviantart.com/brutalityinc/art/Pony-of-Shadows-Custom-MLP-Gimp-Inkscape-941915855
https://www.deviantart.com/dragonmaster137/art/Sonata-Dusk-Siren-Form-532064898
https://www.deviantart.com/fruft/art/Possessed-Stygian-Vector-809015164
https://www.deviantart.com/sketchmcreations/art/Vector-Displeased-Queen-862302810
https://www.deviantart.com/remul-lemlem/art/Vector-100-Nightmare-Moon-516397021
https://www.deviantart.com/bobsicle0/art/King-Sombra-417834114
https://www.deviantart.com/yanoda/art/Tantabus-545703068
https://www.deviantart.com/ajvl/art/No-Magic-Sheep-Only-Dream-558152816
Credits music by Pagan Pegasus, Blitzy, and Namii:
https://poniesatdawn.bandcamp.com/track/the-tantabus-prod-pagan-pegasus