Primordial Sea — Pokémon Ability

Creates heavy rain, which has all the properties of Rain Dance, cannot be replaced, and causes damaging Fire moves to fail.

Effect notes

When this Pokémon enters battle or gains this ability, the weather becomes heavy rain. Heavy rain has all the properties of Rain Dance and also causes damaging Fire moves to fail. Heavy rain ends when this Pokémon leaves battle or loses this ability, or when this ability is nullified. The weather cannot otherwise be changed except by the effects of Delta Stream and Desolate Land. Air Lock and Cloud Nine will prevent the effects of heavy rain, including allowing Fire moves to work, but will not allow the weather to be changed.

In-game descriptions by version

omega ruby alpha sapphireAffects weather and nullifies any Fire-type attacks.
sun moonThe Pokémon changes the weather to nullify Fire-type attacks.
ultra sun ultra moonThe Pokémon changes the weather to nullify Fire-type attacks.
lets go pikachu lets go eeveeThe Pokémon changes the weather to nullify Fire-type attacks.
sword shieldThe Pokémon changes the weather to nullify Fire-type attacks.

Pokémon with this ability