Unmake the Graves [Magic 2015]

Set:	Magic 2015
Type:	Instant
Rarity:	Common
Cost:	{4}{B}

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.)
Return up to two target creature cards from your graveyard to your hand. "I'm raising an army. Any volunteers?"