Ok it starts out at the point of Dainn's Anon-a-Miss story where Sunset Shimmer is beaten and taken to a place outside the city where the group of students continue to beat her. One night its too much and she finally passes on but before her soul go into the after life a being with a past similar to hers offer a second chance
What if when sunset shimmer went through the portal instead of going to the world of equestria girls she instead went to the world of mobius where upon entering becomes a mobian unicorn. at first she tries to pull the same stuff as she did in equestria girls but sonic and his friend saved her from being robotized (at least completely) after that she sees the dark path she heading down she in
What if Sunset Shimmer never forgave herself? What if Sunset Shimmer, even after saving everyone from the sirens, never forgave herself. Even though most of everyone else supposedly did. What if deep down, she feared that everyone else never truly forgave her either. Then one day it happened. Anon-A-Miss struck, everyone turned on her, even her friends, the ones her called her family. Her