Inspired by Undertale.
You were the most ostracized student at Canterlot High School, all because of Sunset Shimmer. She spread rumors about you and even your closest friends abandoned you, never to be near you again. Ever since then, your grades have been dropping drastically, not having the drive to continue trying.
One night, you prayed to whatever god was out there for a way to change your fate, something, anything, to repair the damage done to you. Somehow, your prayers were answered as you now have the ability to "SAVE your progress", like in video games. With this power, you're able to make mistakes, go back, or "LOAD", and start over again, but to do things right.
But as the age old saying goes, "With great power comes great responsibility". When great dangers arrive at CHS's doorstep, it's up to you to undo the damage that isn't your own. But there will be others who will seek your power, and more importantly...
...Where did this power come from?