Wicked Slumber [March of the Machine]

Set: March of the Machine Type: Instant Rarity: Uncommon Cost: {3}{U} 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.)Tap up to two target creatures. Put a stun counter on either of them. Then put a stun counter on either of them. (If a permanent with a stun counter would become untapped, remove one from it instead.)