The Cornerstone Mask is depicted alongside the rest of Ogerpon's masks in the Ogre's Mask card, which was introduced as an Item card in the Pokémon Trading Card Game during the English Scarlet & Violet Series (the Japanese Scarlet & Violet Era). It was released in the Japanese Transformation Mask expansion and the English Twilight Masquerade expansion, with artwork by 5ban Graphics. It allows the player to search their discard pile for a Pokémon ex card with "Ogerpon" in its name, and switch it with another "Ogerpon"-named Pokémon ex card already in play, essentially "changing" its form.
