No divine entity can enter the underworld without in some way dying or taking on an aspect of death. Some live again when they exit the land of the dead, but all leave pieces of themselves behind. Even the King that Crawls could not escape this reality.
    As Torog stabbed like a knife into the heart of death’s realm, it slashed back into him. Where fragments of Torog’s bones struck the earth, formations called godsrock sprouted. These columns of chalky material resemble limestone and rise from the floor at irregular intervals.
    These stony pillars share an echo of Torog’s physical and mental endurance with nearby living creatures, but also mete out excruciating pain to those wracked by other conditions.
    At least one faction of incunabula seeks to locate and record the position of every fragment of gods rock in the Shadowdark. If they know the reason for gathering this information, they aren’t sharing it.
    A godsrock fragment typically occupies an area of 3 to 9 contiguous squares. It can be identified with a DC 25 Dungeoneering or Religion check.

    Effect: A typical square of godsrock is 3 to 10 feet in height, and it can function as cover or blocking terrain, depending on height. Living creatures adjacent to a square of godsrock gain a +2 bonus to Fortitude and Will. In addition, any living creature that fails a saving throw while adjacent to godsrock takes 5 necrotic damage per tier.
    Usage: Adding godsrock to an encounter with several creatures that use powers requiring saving throws allows the necrotic damage to come into play, while also providing living characters with a benefit (as long as they stay near the godsrock, of course).

Published in Underdark, page(s) 119.