Sci-Twi is Twilight Sparkle's twin sister and a minor character of the IG-88's Adventures Series. She used to work for the Horde Of Darkness under her Nightmare Twilight persona until her sister convinced her to join the light and abandon the darkness, which caused Nightmare Twilight to betray her Horde Of Darkness allies, turn back to her human form, and join the good side. She is voiced by Tara Strong when speaking and Rebecca Shoichet when singing.