Swift Swim

Swift Swim is an ability that doubles the Pokémon's Speed stat when it is raining. This means that when rain is active on the battlefield, a Pokémon with Swift Swim will move twice as fast as it normally would, allowing it to outspeed many opponents and potentially strike first in battle. Swift Swim is particularly useful for Water-type Pokémon, as they often benefit from rain-based strategies already and can take advantage of the increased Speed to enhance their offensive capabilities.