Corrupted Roots [Conflux] Magic Player Rewards 2008 Tap all creatures your opponents

Tap all creatures your opponents control

Set: Mirrodin Besieged Type: Artifact Rarity: Rare Cost: {6} Imprint — When Knowledge Pool enters the battlefield

Set: Portal Three Kingdoms Type: Sorcery Rarity: Common Cost: {2}{U} Return target sorcery card from your graveyard to your hand

Then it became a race to exploit the knowledge first

Corrupted Roots [Conflux] Magic Player Rewards 2008 Tap all creatures your opponentsSet: Conflux Type: Enchantment Aura Rarity: Uncommon Cost: {B} Enchant Forest or Plains Whenever enchanted land becomes tapped, its controller loses 2 life. The bones of Jund's dead resurfaced in Naya, poisoning the jungle and killing the sunseeders' crops.