Magical Mystery Cure

The mane six stood in Twilight's house and listened to her speak."From one to another, another to one. A mark of one's destiny singled out alone, fulfilled,from all of us together, together we are friends. With the marks of our destinies made one, there is magic without end." Twilight chanted.Suddenly, the elements sparked bathing Twilight in their light.A tiny explosion filled the house.The mane six screamed.Twilight had vanished!The rest of the mane six looked at the spot where their friend had been standing,it had been scorched with the shape and pattern of her cutie mark.

Somewhere else...

"What happened?Where am I?" asked Twilight."You've done it!Congratulations!" a voice cried out."Princess Celestia,what are you doing here?" asked Twilight."You've completed Star Swirl the Bearded's spell,he couldn't do it because he didn't understand friendship like you did." Princess Celestia smiled and began to sing.

"You've come such a long, long way, and

I've watched you from that very first day.

To see how you might grow, to see what you might do.

To see what you've been through, and

All the ways you've made me proud of you.

It's time now for a new change to come.

You've grown up and your new life has begun.

To go where you will go, to see what you will see.

To find what you will be. For it's time for you...

...to fulfill your destiny!"

Princess Celestia watched  Twilight float in the air.Twilight watched  a shifting blob of magenta energy, a piece of her very spirit, emerge from her chest,and began to swirl around her.. Multiple swirls and pulsing white glows formed and lifted her higher in the air.The whirls of magenta lifted her up and she disappeared.

Back in Ponyville..

In the night sky over Ponyville, Twilight's cutie mark appeared in the sky(now sporting six small white stars instead of the five)  float down to the ground. Twilight's friends watched as the light faded away and Twilight appeared... with a pair of feathered wings!