She wasn't expecting this but after over a thousand years on the moon her mother would be her mother again but she was dead wrong for her mother returned as Nightmare Moon as for poor Rainbow Dash the element of loyalty had to make a decision to keep her mother as the nightmarish ruler who wanted eternal night on the world of Equestria or risk the chance of getting her mother back in front of all of her friends and her aunt who barely exactly knows she is because Luna never said anything about her for over a thousand years as for what her name is and why she is a pegasus instead of an alicorn is easy Rainbow Lunar Dash was born an alicorn but used her magic to hide her horn and shorten her body and make it look like she wasn't immortal like her mother.