Whir of Invention [Aether Revolt Prerelease Promos] Foil You can't choose the same

You can't choose the same card twice

*Weatherlight* navigator

sacrifice it unless you exile another Merfolk you control

except for creatures that couldn't attack

Players can't pay life or sacrifice creatures to cast spells or activate abilities

Whir of Invention [Aether Revolt Prerelease Promos] Foil You can't choose the sameSet: 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.