Hydration

Hydration cures the Pokemon of any major status condition — burn, paralysis, poison, sleep, or freeze — at the end of each turn while rain is active. This means that as long as Rain Dance or Drizzle is in effect, the Pokemon essentially cannot be statused for more than a single turn. The healing occurs automatically at the end of every turn, requiring no action from the player.

This ability pairs exceptionally well with Rest, as the Pokemon can fully restore its HP and then have the sleep immediately cured by Hydration on the same turn, effectively creating a full heal with no downside. However, the reliance on rain makes Hydration situational — if the weather changes or rain expires, the Pokemon loses its status protection entirely. Introduced in Generation IV, Hydration is found on 22 Pokemon, many of them Water-types that naturally benefit from rain-boosted STAB moves alongside their status immunity.