Latias

Latias is an exceptional Tailwind setter thanks to its great bulk, defensive typing, Levitate, and solid Speed. It also checks common threats such as Landorus and Urshifu-R.

Assault Vest Kingambit is a great partner, beating most of Latias's counters like Flutter Mane, Gholdengo, and, to an extent, Incineroar. It also makes great use of Tailwind, and Latias beats most of its counters as well.

Latias can be very tough to remove especially if it Terastallizes into a Poison-type, which, when combined with Levitate, has only one weakness and many valuable resistances. This becomes extra apparent when using Recover, which lets it clean up late-game when positioned well, especially if Mist Ball gets some Special Attack drops.