I do notice that the original series had more villians and some of them were more hardcore than Nightmare Moon. Here's a list of some of them.
Tirek: The first and biggest bad, basically a satan-analogue centaur with a bag of pure evil - it contained a "rainbow of darkness" that would shoot out and corrupt anything it touched, even turning the My Little Ponies into dragon-like monsters. He tried to create an endless night, but a small broken piece of a TRUE "rainbow of light" was enough to destroy him and all his evil forever.
Catrina: Once a pretty nice catwoman/witch, Catrina got hooked on the druglike Witchweed Potion that could turn her into a huge demonic giant that shoots lightning out of her eyes, and cast powerful spells (just like all drugs worth mentioning). She's a slavemaster, forcing people to work in her mines for the ingredients needed to make the stuff, and she's been getting more erratic since it's running low. Eventually she goes too far, and with the help of the ponies and her henchman (actually a friend from the days when she was good) are forced to stop her. Her old friend gets her to kick the habit.
Porcina: a narcissistic magical pig-woman who wanted to admire her own reflection constantly and gained a "midas touch" that turned everything into glass - including terrified ponies (later turned back).
Queen Bumble: a giant queen bee who led an army of giant bees.
Grogar: a goat-like beast who had frickin' lasers that could shoot out of his horns and a magical castle that could teleport between dimensions.
Flores: Evil plants. FEED ME!
Crunch the Rockdog: a GIANT emotionless rock bulldog that controlled living boulders and, oh yes, could turn you to stone with a touch. Turned several ponies into terrified looking statues (they got better).
If any of them do return, it would be interesting to see what they look like with an updated look.
edited 9th Apr '11 3:06:16 PM by SatanicHamster