This is based on Equestria Girls and takes place before twilight is made into an alicorn.
(human content is very light but will come up from time to time. romance will come later in the story)
Steelheart is a high school student who ends up in a huge fight in front of statue in the front yard of Canterlot high. He struggles to get away but is held down as he is slammed against the base of the statue. However instead of crashing into it, there was a flash of light as he fell into the base. Steelheart wakes up in a hospital bed but finds out he is now a unicorn in Equestria.