Here is what I think what should be a theme song for each Pony Freak...
First off with Brutalight...

You're so Creepy by Ghost Town
Rarifruit...

Price Tag by Jessie (Actually thought it might fit her)
Fluttershout...

Wonderwall/Boulevard of Broken Dreams remix
Rainbine...

Technologic by Daft Punk (Since she is a Cyborg)
Applepills...

Pills Here (L4D song)...
Pinkis Cupcake...

Get out alive by Three Days Grace
Derpigun...

Robot Rock by Daft Punk
Creepy Belle...

Insanity
Franciebloom. I actually can't find one. As well as for Karateloo.

I like my theme PILLS

3562335

3526138
Idk, but I chose either these 2 themes for entire EoI.

And also this theme for Rainbine and Derpigun

4322769 Nice.