Death, World’s End

When Death, World’s End enters the battlefield exile two land
At every upkeep Death, World’s End gains a smog counter
At each player’s upkeep that player must pay {p/b} for each counter
{t}: add one {w/b} for each card in the graveyard
{t}: sacrifice Death, World’s End
{t}: remove a smog counter and create a 1/1 black Zombie token