I was racking my brain thinking what set up sweeper could best benefit from the defense Ninetales A's Aurora Veil grants, and I think the answer is Kommo-O. In fact, I'd almost go as far to say the two were made for each other.
Kommo-O has great dual STAB and coverage options, and decent enough coverage. It also fairs well against Tyranitar based Sand Offense and Sun, which is good for Ninetales.
The two have great offensive and defensive type synergy, with the fox resisting ice and being immune to dragon moves, as well as hitting bulky flying, ground and grass types like Landorus, Garchomp, Hippowdon, Tapu Bulu, and Tangrowth with SE Blizzard. It can also hit Defensive Waters like Slowbro, Mantine, Pelliper and Toxapex with STAB Freeze Dry, which is cool. Pun intended!
In return, the lizard resists the Rock and Fire moves Ninetales hates and hits Steels with its Fighting STAB. It also has the option to be immune to Gyro Ball, Sludge Bomb, and things like Shadow Ball with Bulletproof for extra defensive synergy. Its natural bulk also ensures that even without investment, while under Aurora Veil, the only thing that will one shot it is Fairy moves.
But the real icing on the cake that makes the two a natural pair IMO is that Kommo-O has Overcoat. Aurora Veil is great at bolstering both Defense and Sp Denfense, which would be a boon for any set up sweeper, but the chip damage from hail is counterproductive on most sweepers, making the sweeper easier to revenge kill. For example, the hail damage would make pairing Ninetales with other set up dragon sweepers like Dragonite or Charizard X less ideal as the chip damage breaks Multiscale and doesn't go well with Flare Blitz recoil.
Not so with Kommo-O! While it sets up under AV and sweeps, not only is it not taking chip damage, but the hail also damages the opponent's mons, or otherwise negates their Leftovers recovery, aiding the dragon's sweep.
I can't wait to give these two a try together!