This vast structure is crafted of elemental ash, in a region of the Quasielemental Plane of Ash known as the Empty Winter. Most of the Empty Winter is empty black space, deathly cold, with occasional drifting clouds of ash in it. Simply being here drains a person of heat and vitality, like the kiss of an icy vampire, until death comes on numb and painless. The Citadel, though, houses a bit of warmth and light. Constantly collapsing and being rebuilt, the Crumbling Citadel is the special project of the Doomguard faction, and a specific group within that faction who beleive that the multiverse is falling apart too quickly, and that it is the duty of the Doomguard to slow (but not stop) the process.
The major service of the Crumbling Citadel is being one of the only places on the Plane of Ash that most mortals can dwell without special magic or adaptations. As such, it serves as an unofficial launching-point for those that seek to explore the Plane of Ash for one reason or another.
Additionally, there is a group of Doomguard members here that called the Sifters, who spend their time searching through the flowing clouds of Ash, seeking information about what the Plane of Fire is burning. They believe that Fire will consume the multiverse in time, and they see their duty as discovering details about what it has already destroyed. In their sifting, they often discover valuable trinkets either not consumed by Fire or simply lost and adrift in the plane itself. It is even said that the more enthusiastic Sifters occasionally return bits of organic matter back to life, to find out the creature it once was. More practically, they are adept at telling what certain bits of cinder were before they burned, and as such they're useful for spellcasters here, who can purchase spell components particular to the Plane of Ash from them.
The master of the Crumbling Citadel is Devland, Doomlord of Ash (male half-elf, level 14 Fighter, Lawful Neutral), who heads a group of Doomguard members who believe that the multiverse is falling apart too fast, and who seek to counteract this crumbling where they can.
The Crumbling Citadel houses about 400 individuals at any one time. This often includes a collection of Doomguard members (including sifters, builders, followers of Devland, and other factioneers), a few travelers from the Plane of Ash renting rooms, and a handful of ash elementals and undead (whom the Doomguard here maintain good relationships with).
Defend the CitadelEdit
The Doomguard doesn't maintain good relationships with everyone on the Plane of Ash, and the ash xorn and the rasts are certainly not welcome here. Rasts are roam the plane in wild, ravenous packs, and the Doomguard pays well to drive them away from the Citadel. Ash xorn are less openly hostile, but they don't tolerate other folks very well, and the Doomguard are also interested in driving them away from the citadel when they come near.
The Doomguard are generally content to let their losses be losses, but the group under Devland is a bit more aspirational than most. Cavitus, an old citadel of theirs, was taken from them years ago by a powerful lich -- Vecna, before his rise to godhood. Under his leadership, it became a repository for ghosts, spectres, and other incorporeal undead. Vecna has since departed the citadel, but the undead remain, and rumor has it that a great spirit has become leader in his absence based on its ability to tap directly into the Negative Energy Plane. The citadel is rumored to be older than even the Doomguard who inhabited it before, and to hold secrets that even the God of Secrets could not discover, but there is a push within the Crumbling Citdel to liberate Cavitus from the undead, and reclaim it for the Doomguard.