In Gen VII, GameFreak makes it so that Pokémon can naturally have three abilities in the wild instead of two.

Come up with some new abilities to give Pokémon or give existing Pokémon new abilities. They can be simple or broken - there's no limits, though being realistic is always more fun.

Here's an example:
>Flight
>Effect: Gives full immunity to all Ground-type moves.
>Pokémon that gain this ability: Beedrill, Venomoth, Scizor, Dustox, Volbeat, Illumise, Vibrava*, Flygon*, Latias*, Latios*, Golett, Golurk, Volcarona, Genesect
>*Flight replaces Levitate in these cases.

Benefits of this ability include GF being able to make dual-typed Pokémon that fly without having to slap Flying type on them (looking at you, Bug types) as well as making winged stuff without having to worry about it being a Pokémon that's "appropriate" for Levitate.

Simple, possibly redundant, but effective.

Now you guys.