'Rainbow Dash'

"Rainbow Dash" is a protagonist in the Equestria Universe movie. She appears as a mare the way Lightning Blast does. She gets temporary seizures often for an unknown reason.

Equestrial Universe
She appears in her cloudhouse that looks the way Rainbow Dash's cloudhouse does. She looks in the mirror to the human world which actually showed her reflection. She looked like Rainbow Dash with red eyes. She then hid in the position Rainbow Dash did (remember Sonic Rainboom?). She later gained confidence and flew off to find the others. She could only find Lightning Blast by her self. They met eventually and were found out. The look-alike was ambushed by Applejack and the others walked over. They accused her of being a changeling, but she asked what a changeling was and guessed the answer. Lightning Blast tackled Applejack and said she wasn't a changeling. They went to Celestia, where Rainbow Dash turned back and turned back around and flew into the air and zoomed down, she accelerated and eventually did a Sonic Rainboom.

After that, Mane 6 are convinced that she was not a changeling and is given the award Rainbow Dash got in episode 16. Rainbow Dash gets the other and Lightning Blast to read a Daring Do book and the other says "These are just like my adventures. Me and my friends in a treasure hunt and other stuff." The real RD doesn't know if she can believe the other, but it was true.

Equestria Girls
She races Lightning Blast to her cloud house, a book reads about a portal at her house to another reality. She rebels and flies into the portal not paying attention at all, Lightning Blast says she is so rash.

Afternoon, school is over and it focuses mainly on Lightning Blast, who later sees Rainbow Dash about to meet up with her friends just to find out 'Rainbow Dash' "got there before her".

'Rainbow Dash' and Rainbow Dash meet each other and begin to argue, Lightning Blast gets them to befriend each other. The two hang out for a bit, and after the Mane 4 and Lightning Blast have time with each other, they agree to come to Sugar Cube Corner and they all do something together that they like, Applejack suggests a three- legged race, Rainbow Dash suggests a three on four soccer game, and Rarity suggests a party with fruit punch and cucumber sandwiches.

Somehow, the Mane 5 are disappearing altogether. They find out the human version of Discord tried to change them. Rainbow Dash and Lightning Blast are defeated defeated until later turning into their half-pony form and 'Rainbow Dash' defeated Discord by blasting him.

Equestria Girls 2
Sometime after defeating Discord, Rainbow Dash keeps asking questions and  tried to answer them about how Discord got here, Lightning Blast tells her to stop  worrying and says he is a "fool, because of his face". Rainbow Dash laughs and stops worrying about it. Rainbow Dash goes to sleep in class, dreaming about her in half-pony form with a larger wingspan, feels lighter, and lighter skin color, her hair up. She is suddenly woken up by Ms. Harshwinny.

She refuses to speak until lunch, where Rainbow Dash says she is acting like Fluttershy, Lightning Blast and 'Rainbow Dash' quickly leave and go have conversations on the soccer field. After being caught by Cranky Doodle Donkey, 'Rainbow Dash' and Lightning Blast make their way for the school entrance and when they get to class they get a detention. Rainbow Dash offers to race the two to the end of the soccer field with a string for the finish line. They tie (despite 'Rainbow Dash' finishes first way ahead of the two (shown on the camera photos Applejack has that show a few scenes of 'Rainbow Dash' jumping over the string and doing a few poses at the camera, it is never seen if she actually does all of these actions). Discord is seen behind the  They do a few things to make 'Rainbow Dash' feel better.

They throw a party for their last thing (Rarity's suggestion in the previous movie, but additional foods and drinks (tropical punch, water, pie, cake, etc.). Discord opens the roof and they go into their half-pony forms and face him off and everyone is defeated except 'Rainbow Dash', her body floats up in a rainbow-colored ara and fights Discord. She performs a Super Sonic Rainboom and finally defeats Discord with the addition of a rainbow blasts.