The mild shocks it delivers through its paw pads have a healing effect. It can use slightly stronger shocks to revive fainted Pokémon.

ABILITY: Defibrillator: Can revive an ally once when the Pokémon's HP is full. If this Pokemon is a Nursa at full HP, after an ally faints, it stays on the field and is immediately restored to 1 HP. This can only be activated once per battle. This Pokemon then loses 1/8 of its max HP. This ability cannot be Traced or gained by Role Play, replaced by Worry Seed or Simple Beam, exchanged with Skill Swap or given to another Pokemon by Entrainment.

For more information, see its entry on the Pokemon Flux Wiki.