Take two self acclaimed fastest things alive, add a monster that lives to consume and absorb and a couple of friends that have a tendency to put themselves in the middle most of their worlds problems and what do you get... the answer, this. (to clear any confusion, the story takes place directly after the events of Equestria Girls.)
An extra from my other Sonic/MLP story, Sonic the Stallion. When Fluttershy and Tails are sent to Cloudsdale in search of one the chaos emeralds brought to Equestria, they find themselves tossed into a nightmare, when they find out, just where the emerald was taken.
Twilight knows how much she cares for her friends and how much she would do for them. Somewhere along the line, she seems to have forgotten just how much she means to them. (to avoid confusion: the characters are in human form, despite the terms they use)