Unlimited Power

Target creature gets +X/+X where X equals the number of cards in all graveyards until the end of the turn. Damage cannot be prevented by target creature until the end of the turn.
The scores of dead have nourished my power further. You cannot stop me "heroes." Behold my power and tremble. Observe the temple and weep. For this shall be your grave.
-Zarth, the Evermore