Yeah, I'm not going by that. I know it's in the comics, even though I haven't read them, and it's how Nightmare Rarity comes to be. But a moon parasite is way too Venom (from Spider-Man the 90s' cartoon) for me. Besides, I think having Luna be generally jealous of her sister adds a bit of depth to character. Now I love Luna; I think she's an awesome character, but I love Nightmare Moon more. Nightmare Moon was one of the only true villians of the show. Discord just wanted chaos and to have a good time while making Celestia's life difficult. Sombra could only ever hiss out, "Ponies." Chrysalis, just wanted food for her subjets and wanted no one stopping her. Nightmare Moon on the other hand wanted to take way the sun and have ever lasting night. By having only night the land would freeze and everyone would die. That is why, Nightmare Moon is truly bad ass.