Most of my favorites aren't exactly Champion material, but I'd definitely have an Eviolite Porygon2 and Slush Rush Alolan Sandslash. Next to that, maybe Flygon, Volcarona, Prankster Meowstic, and... Lickilicky?
I prefer Frosmoth over Volcarona but opted for the latter for more coverage. Also, though I hate Lickilicky's aesthetic, I included it to represent my love for Lickitung (and because remember having a little bit of trouble with Nishino's Lickilicky in BW2).
I'm not a competitive player, but the idea is that Meowstic-M could potentially set up a super defensive Porygon2 with its dual screens, A-Sandslash could Rapid Spin out Stealth Rock that may otherwise cripple Volcarona, and Porygon2, A-Sandslash, and Lickilicky would all have an Ice-type move in case the player is running OU/Uber Dragon-types.