Nightfall Twinkle is Twilight's pre-princess self and a hero from another dimension.
Nightfall Twinkle was Twilight's name before becoming a princess. When Optimus Prime, Ryan F-Freeman, and Twilight Sparkle defeated Unicron and returned him to stasis with the Matrix of Leadership, the magic of Ryan's Keyblade and the Magic of the Alicorn, Optimus and Twilight lost their memories of being a Prime and a Princess. While Ryan got both their memories in his head, he learned their pasts and sought to fix the
Nightfall looks like Princess Twilight Sparkle. In pony form,