Cartes permettant de doubler le nombre de manas

Divergent Growth {G} Instant Until end of turn, lands you control gain "{T}: Add one mana of any color to your mana pool."

Doubling Cube {2} Artifact {3}, {T}: Double the amount of each type of mana in your mana pool.

Extraplanar Lens {3} Artifact Imprint -- When Extraplanar Lens comes into play, you may remove target land you control from the game. (The removed card is imprinted on this artifact.) Whenever a land with the same name as the imprinted card is tapped for mana, its controller adds one mana to his or her mana pool of any type that land produced.

Mana Flare {2}{R} Enchantment Whenever a player taps a land for mana, that player adds one mana of that type to his or her mana pool.

Upwelling {3}{G} Enchantment Mana pools don't empty at the end of phases or turns. (This effect stops mana burn.)