Crustle VS Cornerstone Mask Ogerpon

Leonatoz72

How do these two Pokémon interact in the Active Spot?

DoubleCure

Ignoring effects on the opponent’s Pokemon takes precedence over any and all damage reduction effects, including preventing the damage entirely.

So Cornerstone Mask Ogerpon ex attack can damage Crustle despite its ability.

Pokémon342548

For Ogrepon, do you mean that it's the "ex" one?