The Sea of Corpses

When The Sea of Corpses enters the battlefield,
Sacrifice it, Unless you sacrifice two nontoken
creatures.
{t}: Add {b}
{b/g}, {t}: Tap any number of untapped Blessed
Lands you control, Abyssal creatures you cast
this turn cost {x} less to cast this turn, Where X
is the number of Blessed Lands tapped this way.