Collective Inferno ECL/387

Set: Lorwyn Eclipsed
Collector Code: ECL/387
Name: Collective Inferno
Type: Enchantment
Oracle text: 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.
Rarity: Mythic