Sunset Shimmer

Sunset Shimmer is the main villain of My Little Pony: Equestria Girls, and a supporting character in the sequels, some of the short films, and web series. She also appeared in the IDW comics where her backstory is detailed. She is voiced by Rebecca Shoichet, who also voiced Sugar Belle and Night Glider.

Biography
According to Hasbro's official backstory, Sunset Shimmer was the first and only daughter of Mr. and Mrs. Shimmer and also the former student of Princess Luna's older sister Princess Celestia (Nicole Oliver).

Planning to kill Myrtle Edmonds, Elena, Yuki, and Teresa
Sunset Shimmer had sent her two cronies, Snips (Lee Tockar) and Snails (Richard Ian Cox) respectively to find a treasure on a Chinese land in Hawaii. The rich, selfish, unfriendly, and spoiled red-haired girl named Myrtle Edmonds (Liliana Mumy), along with her friends Elena, Teresa, and Yuki came to steal the treasure from the natives and bring it to Sunset. However, Myrtle fell in love with Sunset's ex-boyfriend Flash Sentry (Vincent Tong). Sunset had Myrtle, Elena, Teresa, and Yuki murdered seven years later.

Planning to kill Bradley "Brad" Morton and Officer Morton
Sunset had sent her two men to find a treasure on a Spanish land in St. Augustine, Florida. The spoiled, greedy, dishonest, selfish, and unfriendly blond-haired teenage boy named Bradley "Brad" Morton (Matthew Nolan), the only son of Officer Morton (Dee Bradley Baker) and Mrs. Morton, who came from New York City was to steal the treasure from them. However, Bradley Morton seemingly fell in love with a blonde-haired teenage girl named Rose (Mae Whitman), who also came from New York City. Sunset had both Bradley Morton and his father Officer Morton killed six yeas later.