Contamination [Urza's Saga] Unlimited Edition Creatures those players control that

Creatures those players control that can block additional creatures may likewise be put into additional piles

Roar of the World is in the command zone or on the battlefield

and the second player controls the first player during the first player's next turn

−10: Target player mills twenty cards

it gets +3/+3 until end of turn for each creature blocking it beyond the first

Contamination [Urza's Saga] Unlimited Edition Creatures those players control thatSet: Urza's Saga Type: Enchantment Rare Cost: {2}{B} At the beginning of your upkeep, sacrifice Contamination unless you sacrifice a creature. If a land is tapped for mana, it produces {B} instead of any other type and amount.