Sunset Shimmer never intended to hurt anyone. She simply had a dream of who she wanted to be. And nothing's more gut-wrenching than realizing real life simply doesn't include your life-long dream...
An origin story for Sunset Shimmer, as a basis for her episode of the Not Exactly Friends series. (Note: I treat the comics backstory as helpful guidance here, rather than canon.)
For more in this timeline, see: Sunset -- Part II