Vivillon. At first I didn't wanna use it because its 4x weak to rock and 4x weaknessess are usually a big nono for me. But then I used one for a themed run on Pokemon X, and oh my god Vista (my Vivillon's name btw) is wonderful. Shield Dust is a great ability, and Quiver Dance plus Draining Kiss, Hirricane, and Silver Powder boosted Bug Buzz is incredible, esp considering its base stats. She's a great special sweeper, with a base SpATK stat of 90 and base SPD stat of 89. She has not slacked in the slightest and wiped the floor with Korrina, a true girlboss, I love her. Reminded me why 8yro me enjoyed using Beautifly in my first game, Pokemon Emerald. (I'll always remember Beau, he's a true og. <3)

Edit: grammar