Whir of Invention [Aether Revolt Prerelease Promos]

Whir of Invention [Aether Revolt Prerelease Promos]Set: Aether Revolt Prerelease Promos Type: Instant Rarity: Rare Cost: {X}{U}{U}{U} Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.) Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.

Set: EX: Crystal Guardians Type: Fire Rarity: Uncommon Retreat cost: Colorless

the Lost Prince has 3 or more rust counters on it

Set: XY: Ancient Origins Type: Supporter Rarity: Promo

Selenia was freed from her magical bindings by the wealthy noble

Set: Sun & Moon: Base Set Type: Grass Rarity: Holo Rare Retreat cost: Colorless

destroy target artifact

Set: Sun & Moon: Celestial Storm Type: Fire Rarity: Secret Rare Retreat cost: Colorless

you may put a fuse counter on Powder Keg

Set: Portal Three Kingdoms Type: Creature — Cat Rarity: Uncommon Cost: {2}{G} Whenever Hunting Cheetah deals damage to an opponent

Cao Ren was known throughout the three kingdoms as the fiercest of warriors

sacrifice Junún Efreet unless you pay {B}{B}

Set: HeartGold & SoulSilver: Base Set Type: Supporter Rarity: Uncommon