You can get the Ability Patch as a drop in Pokémon Scarlet and Violet and use it to change a Pokémon's ability to its Hidden Ability. This is more handy for competitive players as it can buff certain moves and give you a slight advantage in battles. For example, you can evolve Quaxly into Quaxwell and Quaquaval, after which the Fighting- and Water-type Dancer Pokémon might learn Torrent. However, Quaquaval's Hidden Ability Moxie is arguably better, as it temporarily bolsters the attack by one stage whenever it knocks out a Pokémon.

https://screenrant.com/ability-patch-pokemon-scarlet-violet/