Plane of Metal

Cut off from the rest of the cosmology since prehistory, the Plane of Metal has only recently returned to it. Still resuming its ancient form, it wedges between the Plane of Earth and the Plane of Water, vast in scope but still expanding. Metal of every kind, liquid and solid, decaying cityscapes and intense magnetic fields make up its chaotic structure, and it exists in a state of ongoing change and decay that leaves plentiful pockets of air for a visitor to breathe in. A creature entombed in the plane's substance risks suffocation unless it can phase through metal.

Its creatures reflect the jumble of forces they live among: many have fluid forms of flowing metal or inhabit clouds of rust, and the plane's genies stage bold performances keyed to its dissonance. Its elemental lords embody the slow disintegration of their home, dispirited since an invasion from the Plane of Earth preceded the sealing of their plane, and they have offered no clear vision of what it might now become.