This story is a sequel to Futures
John Smith wakes up in a hospital with an alicorn watching over him.
He remembers his last mission with Princess Twilight Sparkle. He remembers being hit by a magical backlash and hitting something hard. He feels different, the world feels different to him.
And now Luna has a mission. Stop the war that killed Celestia.
Expect more than a few Doctor Who references. Guess this will be my own origin story for Dr. Hooves.