The final fight against Skrung and his servants is almost over (after three epic sessions of hellish combat), and, assuming things don't suddenly go horribly wrong (which, given the sheer power of the enemy, they still could), the group stand to get some potent rewards. One reward is a boon that they will be granted by the Morgog'Gigorim King Malogg; the ability, once every five days, to assume the Stone Soul Stance.
When in this stance, the character becomes encased in heavy plates of solid stone. It slows them down and trashes their manual dexterity, but turns them into a tank. Obviously, for the less tankish in nature, there is an option to end the stance for a butt load of temporary hit points.