It rock if Flurtershy and Dyscord had a daughter. Someone with Dyscord’s brains and powers as well as his sense of humour, but also Flurtershy’s virtuous heart and ability to understand animals as well as her singing voice. It be sweet also if the daughter did the copy thing her dad did when pondering amny ideas and dilemmas.
Lara Jill Miller who did Kari Kamiya on Digimon be one grand choice for her. Something to fit her sass, her gentleness, her intelligence, and her humour.
If she appear on Gen 5, it rock if she lent a hand to them.

@Background Pony #D485  
“Yes, me. Me, me, me.” “Me too.”

I’m startin’ with the mare in the mirror!

Dancin’ with myself.  
Shadow clone jutsu.  
“The gangs all here.”  
“All I wanna do is have some fun, I got a feeling I’m not the only one…”  
“When will my reflection show who I am inside.”

@FamusJamus  
Now think about each of those changelings who took Fluttershys form right there, but now as reformed changedlings.  
Can they still take her form and act out her personality?

Nice touch with how each reflection looks different.

You’re never too young to have a changeling flashback.