Collective Inferno 363 (Lorwyn Eclipsed)

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.) As this enchantment enters, choose a creature type. Double all damage that sources you control of the chosen type would deal.

NM - $3.00
LP - $2.50
MP - $2.00
HP - $1.50
DMG - $1.50