When you can turn into a literal demon, chances are you’re pretty evil, and Sunset Shimmer certainly was in her time. She was quite creative with her meanness as well, as poor Rarity and Applejack have had the misfortune of finding out in the locker room. Girl’s stronger than she looks.
 
Applejack is more than a little miffed to find herself stuck up here in - and by - her underdrawers. Poor Rarity is more concerned about her own stretching out. She’s rather fond of these panties.
 
My that’s a lovely mirror.
 
Granted not long after she had her change of heart, Rarity and Applejack had to repay the favor to Sunset