Ulnex Arhun

The realm on the other side of the Maw. Glimpsed by the party for the first time in Session 12, when the Slanted Circle’s resonator activated and tore a doorway in the sky.

What the Party Saw

When the Maw opened above the Xen’Drik leynexus:

• A beam of ley energy speared from the ground straight into the sky
• The sky cracked open into a door at the beam’s apex
• Through it: stars, galaxies, upside-down towers floating in space
• A colossal tail drifted across the view — and then through the Maw itself
• A solitary figure (the Slanted Circle Mage) descended from Ulnex Arhun into Eberron through the open Maw

The party did not enter Ulnex Arhun. They saw it. And they closed the Maw before more came through.

What It Suggests

The realm appears to be physically connected to Eberron when the Maw is open — not a vision, not a projection, but an actual planar adjacency that the Maw Frame bridges. The Mage stepping bodily through the door confirms it.

The presence of upside-down towers in space hints at a constructed realm, not raw void. Someone — or something — built there. Whether those structures are ruins, prisons, or something still inhabited is unknown.

The colossal tail glimpsed through the door belongs almost certainly to Vorthalax — the Sleeper Beneath Stone — implying that the entity’s body extends across the planar boundary. Its head and front mass sleep beneath Xen’Drik. Its tail, perhaps far more, extends into Ulnex Arhun.

The Circle’s intent in opening the Maw permanently appears to be not to invade Ulnex Arhun, but to give Vorthalax room to uncoil — to let the Sleeper take its full form by waking it across both planes simultaneously.

Etymology

The Mage spoke the name as if it were familiar — “the other end of the Maw — Ulnex Arhun” — without explanation, as though he expected the party to either know it or to never need to. The phonology resembles no language the party has encountered: not Common, not Druidic, not the Drow’s tongue, and not Giant. It is possible the name comes from the same forgotten era that built the Maw Frame itself.

Status

Currently sealed. The Maw closed at the end of Session 12 after the Slanted Circle Mage was killed and Rook stepped through to deliver his counter-monologue. Whether the Frame can be opened to Ulnex Arhun again — and by whom — is the open question of Arc 2.