Herald of the Obzedat

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.)
Flying
When Herald of the Obzedat enters the battlefield, sacrifice each creature that convoked it. For each creature sacrificed this way, create a number of 1/1 white and black Spirit creature tokens with flying equal to that creature's toughness.