The Netherworld is the original home of the Rephaim. It was once a waystop between Earth and the æther, but has now fallen into a state of decay.
Description[]
The Rephs emerged, fully formed and conscious, from the Netherworld. Nothing grew or perished there, and its inhabitants did not age, because they were made of sarx, not mortal flesh, and time had no power over their realm. Now and then, more Rephs would surface through unpredictable waves of creation.
The Netherworld was a halfway point between the realms of life and death, where human spirits were able to come to terms with their deaths and prepare for the journey to the last light. This stopped them from lingering on Earth, which raised the ethereal threshold. The psychopomps would lead the human spirits into the Netherworld. However, humans killed each other so frequently that the corporeal world became overpopulated with drifting spirits, overwhelming the psychopomps. The Mothallath family intervened, since they alone, among the Rephs, could walk across the veils and visit Earth.
The ethereal threshold broke in 1859 in an event is known as the Waning of the Veils, which caused the Netherworld to begin rotting and the Emim to appear. It is now decayed and essentially uninhabitable, though some Rephs do still try to live there, and essence of amaranth and Emite blood (alysoplasm) can still be harvested.
Warden describes the Netherworld to Paige Mahoney. The buildings are colossal and carved from iridescent stone. Cities shine like shattered glass. The main river is the Grieving and has a bed of pearl-like pebbles. Rephaite weapons are made of a Netherworld element named opaline. It's the only substance that can hew through Rephaite bone. Besides the Rephaim, there are sarx-creatures that inhabit the Netherworld. One of these creatures is called the chol-bird. It's a winged sarx-creature that are companions of the Rephaim and can travel to Earth in spirit forms as psychopomps. The Fall is the door to the æther from that realm. When spirits were ready to accept their deaths and go to the last light, the Rephaim would lead them to this chasm and the spirits would cast themselves over the Fall.