Whir of Invention [Aether Revolt Prerelease Promos] Water[+10] when your opponent activates a

when your opponent activates a Spell/Trap Card

You can only use this effect once per Duel

Set: Expedition: Base Set Type: Psychic Rarity: Uncommon Retreat cost: Colorless

This card cannot attack during the turn you activate this effect

Set: HeartGold & SoulSilver: Unleashed Type: Fire

Whir of Invention [Aether Revolt Prerelease Promos] Water[+10] when your opponent activates aSet: 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.