Chord of Calling [Magic 2015] Coaccion sacrifice Koskun Falls unless you

sacrifice Koskun Falls unless you tap an untapped creature you control

Set: Arena League 2000 Type: Sorcery Rarity: Rare Cost: {1}{R}{R} Destroy target artifact or land

as standing in a dictionary

Set: Mercadian Masques Type: Enchantment — Aura Rarity: Common Cost: {2}{G} Flash

Chord of Calling [Magic 2015] Coaccion sacrifice Koskun Falls unless youSet: Magic 2015 Type: Instant Rarity: Rare Cost: {X}{G}{G}{G} Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.) Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.