The Sea of Blood was a region near the Wastelands in the Realm of Outworld. It is later changed to a location within the Netherrealm, a large, bottomless body of water that is only passable by some. This entire lake was filled with blood. The souls of the dead that are there are put to use with their bodies added to the sea of the blood of the damned. The sea is also bottomless; those who fall in it can never escape.