Cornerstone Mask Ogerpon EX is a Secret Rare Pokémon trading card from the 2024 Pokémon TCG Scarlet & Violet: Twilight Masquerade expansion. The striking alternate-art illustration by Yano Keiji shows Ogerpon wearing its ritual mask in a prismatic, moonlit mosaic style; the card’s shimmering holofoil background and silver borders accentuate its alt-art rarity. As a Basic Fighting-type Tera Pokémon EX, it has 210 HP, the Cornerstone Stance Ability to block damage from Ability-based attacks, and a 140-damage Demolish attack. Collectors prize this card’s holofoil artwork and secret rare status, and it stands out as one of the first TCG appearances of the legendary masked Pokémon Ogerpon.