Derevi, Empyrial Tactician (Foil Etched) [Commander Legends] Secret Lair Drop Promos or the creature's toughness

or the creature's toughness

Set: Mirage Type: Instant Uncommon Cost: {U} Search your library for an instant or sorcery card and reveal that card

When Knowledge Vault leaves the battlefield

Set: Dominaria Prerelease Promos Type: Artifact Rarity: Rare Cost: {5} {T}: Add three mana of any one color

create two 2/2 green Ooze creature tokens

Derevi, Empyrial Tactician (Foil Etched) [Commander Legends] Secret Lair Drop Promos or the creature's toughnessSet: Commander Legends Type: Legendary Creature Bird Wizard Mythic Cost: {G}{W}{U} Flying Whenever Derevi, Empyrial Tactician enters the battlefield or a creature you control deals combat damage to a player, you may tap or untap target permanent. {1}{G}{W}{U}: Put Derevi onto the battlefield from the command zone.