https://www.furaffinity.net/user/blackheartzer0/
Two months pass since that fateful day, and Rainbow Dash's birthday has come up. The problem? Everyone insisted that they have the party in Cloudsdale, and Twilight Eclipse aren't coordinated enough to fly yet.

Luckily, Twilight has an idea on how to restore their flying ability, at least until they get to the party. So without bothering to read the warnings since they were in a hurry, Twilight and Solar cast a spell to briefly join their minds together and allow them to function perfectly as one.

Thing is, if the spell is maintained for too long, personalities and feelings begin being blended together. How long is too long? certainly not enough time to make it from Ponyville to Cloudsdale, that's for sure! Hilarity ensues.