Forsaken World

{t}: Sacrifice a creature. Target player sacrifices a
land. You lose two life.
{t}: Add X mana to your mana pool, where X is
the number of lands in all players discards.
{3}{t}: Sacrifice Forsaken World. You gain X life,
where X is the number of lands in all players
discards.
When Forsaken Void enters or leaves the battlefield, each player sacrifices a creature or land.