The song is based around Luna becoming Nightmare Moon. It's a Villain Song set before and during Luna's descension into villainy.
In 2016, Youtuber "Duo Cartoonist" posted an animation for the revised version, with Eileen Montgomery providing the vocals.
This song and its animation provide examples of:
- The Cameo: Star Swirl the Bearded makes an appearance in this video, despite that (as revealed in Season 7), he had disappeared before Nightmare Moon's first appearance.
- Content Warnings: The animation starts with a mock rating screen stating that the animation is a fan work and that it's suitable for all audiences
- Evil Is Hammy: The first thing Nightmare Moon is have a hammy Evil Laugh.
- Evil Laugh: Nightmare Moon has an evil laugh at the end of the original song.
- Evil Sounds Deep: Luna's voice turns noticeably deeper after transforming into Nightmare Moon. This is a change added in covers of the song and the animation. In the original song and the revised version Luna's voice remains the same.
- Fan Animation: Duo Cartoonist's short film version is a fan animation.
- Ominous Latin Chanting: "In umbra Luna est".
- Villain Song: It's a Luna villain song where Luna slowly turns into Nightmare Moon.