Collective Inferno - Lorwyn Eclipsed #363

Collective Inferno

Set: Lorwyn Eclipsed (ECL)
Collector Number: 363
Type: Enchantment
Rarity: Rare
Mana Value: 5.0

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.