It seems to be a separate realm from the Underworld that other supernaturals access.
Most Arisen have no memory of Duat. Besides a death-cycle, they have no way of entering it.
According to Iremite texts compiled in “Dreams of Avarice”, a tome compiled by the Heretic who has achieved Apotheosis and perfect memory, Duat was created by the Judges to judge the souls of dead humans and gather those dead that would be sacrificed to Ammut. It is connected to the Nebtet, the blood-spring, and was originally protected by the god Anpu. Through the scheming of the Shan’iatu, Azar descended to Duat and became its king, while Anpu became its guardian wandering Neter-khertet.
Besides the Judges and the “successful” Shan’iatu, Duat is home to host of various creatures that are described as “demons” by Iremites, creatures that serve the Law, but are not alive. Among these are the Slaughterers, who, armed with stone knives, prey on those dead with weak Pillars. Scarab-headed creatures guard its entry and will fall upon anyone who tries to enter without Anpu’s guidance. Other include creatures like the Black Huriyah, which is summoned through Utterances.
Duat is organized into several “circles” and waystations, similar to the Egyptian underworld it would inspire. The first stop is death itself. Upon death, the soul feels compelled to reenter its body. Should this be done, its Pillars will dissolve and form ghosts and similar half-living things. The soul has to withstand this urge and continue to Neter-khertet (the Iremite term for Twilight). There, the soul has to call for Anpu to open the way westward, or fall prey to creatures that dwell in that state, like ghosts and spirits. In return for knowledge of Anpu’s True Name, which is inscribed upon the Sekhem of the living, the soul will enter Duat. This is considered the “First Gate”.
Duat itself is described as a black and red desert, with seas made of fire and oases with poisonous flowers. The soul has to continue to travel westwards, with only the stars to guide it. To withstand the rigors of the way, the soul has to bury itself under the sands to escape the flames, or accept the pain it brings. After enduring the exertions of the journey, the soul will reach black gates made out of metal. Here, it will be tested in order to progress. The Second Gate tests the Ab, through confronting the soul with past loves, enemies and wild passions. The Third Gate tests the Ba, by throwing natural obstacles against the soul that it will have to overcome. The Fourth Gate tests the Ka, by submitting the soul to tortures to prove its endurance. The Fifth Gate tests the Ren, by presenting the soul with riddles that force it to justify its own Name. The Sixth Gate tests the Sheut, which tests the knowledge of the soul in Irem’s mysteries as presented by the Guilds. Beyond the gates lies the City of Black Spines, the capital of Duat and the residence of the Judges and Azar. At its center lies the Seventh Gate, also called the “Place of Slaughter”. Here, Azar sits upon his throne and Shezmu awaits to crush the sinners into wine for the gods. The Judges of Duat will test the soul until it makes its Decree before one of them. If he does not, then Shezmu will crush it.
Those sanctified by the Rite of Return will then reawaken from their slumber. Souls of mortals that have come so far have earned a residence in the City of Black Spines or (if they manage to draw upon the Will of Sutek) ascendance to A'aru. Needless to say, almost no one manages that feat.
- , p.20-21
- , p.8, 38-42