Midnight Sparkle was ripping holes to another dimension, however Sunset would be far more experienced with Magic and fighting then Midnight for sure. (Equestria may be peaceful for the most part but The Everfree Forest and the creatures in it do exist) Also I just can’t see the Element of Magic being weaker than stolen magic from the Human Mane 5 and Sunset.

Well Midnight Sparkle easily wins when it comes to looks, but I think she would also win in battle. She could tear apart reality and if it wasn’t for Spike’s puppy eyes distraction she would have defeated Daydream Shimmer (as storyboard artist Lunchie says she’s called now).

And the winner is… THE GREAT AND POWERFUL TRRRRRRRRRRRRRIXIE

This could be interesting.
 
Midnight Sparkle looks cooler.

They would be interesting to draw together.

Midnight Sparkle, simply because it’s a much better design.

I’d give this one to Satan for having direct connection to most powerful font of magic known in comparison to a bunch of pilfered chaotic magic, and generally being more violent with it.