Red Star is no normal mare. Having chaotic magic in her blood, she was born with bat wings and sharp fangs. After meeting Armored Heart, the son of Shining Armor and Princess Cadence, she finds that every creature and pony has the chance to live a perfectly normal life.

Red Star has always felt out of place, but her family has always accepted her for who she is. The citizens of Ponyville, however… She meets a young stallion from the Crystal Empire, the prince, who surprises her with his kindness.
She visits the Crystal Empire often to see him, and one day he decides to share with her the knowledge of a magic mirror. They find a magic door that shows them their worst fear, and Red Star accidentally discovers a cursed crown.
The crown drives her to achieve her most evil goals. It promises her beauty in exchange for control. She attempts to conquer the Empire and gets extremely close, all the while becoming more and more of a monster. It's up to Armored Heart, prince of the Crystal Empire, to bring her back.