Shield Dust

In detail

This Pokémon is immune to the extra effects of moves used against it. An extra effect is a move's chance, listed as an "effect chance", to inflict a status ailment, cause a stat change, or make the target flinch in addition to the move's main effect. For example, Thunder Shock's paralysis is an extra effect, but Thunder Wave's is not, nor are Knock Off's item removal and Air Cutter's increased critical hit rate.