Unmask [The List] Human Elf Druid creatures can't attack unless their

creatures can't attack unless their controller pays {X} for each attacking creature they control

Set: Ravnica Allegiance Prerelease Promos Type: Instant Rarity: Rare Cost: {3}{U}{U} Draw three cards

Set: Core Set 2020 Type: Creature — Human Knight Rarity: Uncommon Cost: {3}{W} Whenever you gain life

Set: Iconic Masters Type: Creature — Sphinx Rarity: Rare Cost: {5}{U}{U} Flying

Unmask [The List] Human Elf Druid creatures can't attack unless theirSet: The List Type: Sorcery Rarity: Rare Cost: {3}{B} You may exile a black card from your hand rather than pay this spell's mana cost. Target player reveals their hand. You choose a nonland card from it. That player discards that card.