@Phantom Rider  
Then consider Sweetie Belle as Elina by default.
 
Then Rarity becomes the Mysterious Phantom Warrior Maria, as of Vanquished Queens and QR Rebellion.
 
Oh, and attack name “DRAGON TAIL!!”

Epic Rarity is epic! I especially love seeing her like this because of how often we see her leap into a fighting position. And the fact that it’s a learned skill, that she has an actual stance, makes it say more about her.
 
See, when the others fight they’re using what they already have. AJ and Dash use already being the strongest and the most atheletic to their advantage in hitting things. Twilight has pew pew lazors as one of her zillions of spells which she knows as a lover of both magic and learning. Pinkie uses her ever-present chaos magic more deliberately in a pinch (yes, she can! Honest-to-Celestia spider-sense in The Mysterious Mare Do Well, using her party cannon as a real cannon against changelings…) Fluttershy… uh… well, she doesn’t hit things, but if I didn’t mention her name after ALL THIS, it’d sound like I forgot her. It’s okay, Shy, we still love you.
 
Rarity, on the other hand? She has a skill that exists only for combat, one you need time and effort to get good at and maintenance to stay good at. She made the decision to set out and learn how to get really good at hitting things.
 
tl;dr: Rarity is most badass pony.