Shattered Story

Formerly Bedtime Story, she and her family (once blessed by Princess Luna) used to aid in making dreams while Nightmare Moon was locked away. When Nightmare Moon escaped, Story was one of the first to attempt to slow her assault, and she got blasted by a terrible curse that corrupted her dream magic. Now, she is cursed to bring others' nightmares to life in terrifying apparitions if she spends too much time around them, and her fear of hurting those around her has caused her to retreat to solitude, even rejecting offers of help from the princess she once served. 

Although she was once a unicorn, her horn was blasted away with the force of the magic that cursed her, and she has since developed strange, unsettling wings made of magical energy. Without her horn, any magic she attempts to cast comes out unfocused and unregulated, which can be dangerous.