Citadel Exhalus is an impressive fortress tethered to a thread of nothingness to the Quasielemental Plane of Vacuum where it borders the Negative+Energy+Plane. Meditative members of the Doomguard go to its unprotected platform (which is surrounded by a barely breathable bubble of air) to contemplate what they call the End, the logical conclusion of entropy. This is dangerous, as devouring quasielementals and other spirits of the plane are not prevented from swooping in and attacking.
The citadel is ruled by Doomlord Nagaul, a grim and tense female dwarven worshipper of Siva. Nagaul believes that entropy is going along at exactly the right rate and does not currently need to be slowed or hastened. The Doomguard of Citadel Exhalus have been allying themselves with those of the Crumbling Citadel in the interest of restoring the faction’s strength. Indeed, were it not for their efforts, the faction might have fallen apart entirely by now. Of course, in a decade, they might be working to halt the growth of the faction… if it survives that long.