Nightmare Moon

Nightmare Moon is a evil verison of Princess Luna from "My Little Pony: Friendship is Magic".

Nightmare Moon played Darth Vader in Star Wars (Twilight'sSpaceStar17 Style)
She is a Sith Lord

Nightmare Moon played Wuya (in ghost form) in Xiaolin Showdown (Twilight'sSpaceStar17's Animal Style) & Xiaolin Chronicles (Twilight'sSpaceStar17's Animal Style)
She is the ancient Heylin spirit

Nightmare Moon played Zira in The Cartoon Dog King ll: Courage's Pride
She is a evil lioness

Nightmare Moon played Pac-Man in Nightmare Moon and the Ghostly Adventures and Mission ImNightmare Moonable!
She is a hungry unicorn

Nightmare Moon played Astronema in Power Ponies In Space
She is Andros' Sister's Evil Alter Ego.

Portrayals
Nightmare Moon is played Mewberty Wander in My Little Star: Friendship is Power!