Limbo, also known as the In-Between, The Land Between, and the Ethereal, Limbo was a home for Lost spirits and those who mistakenly wander between worlds. Thanatos and His Azrael frequent this realm, in search for these lost souls, in order to guide them to the Underworld through the River Styx, which flows through the realms, by opening a river bank and summoning the Ferryman Charon. The guide of souls boards Charon’s vessel and escorts the soul(s) to the City of Penumbra. It is unknown whether Thanatos himself completes this journey or summons one of his Azrael servants- without questioning the God of Death or his Choir directly, not many souls that have completed the full journey are able to recount the full travel, even should they be willing.
Charon, The Ferryman, he ferries souls through the underworld at the behest of Aetien, Thanatos and Hades, and performs his task well, protecting the Souls in his charge from harm, and the dangers of the In-Between itself. He wields not only formidable magic prowess, but is equipped with a mighty oar he uses to beat uncooperative souls and interlopers alike. Should a traveler between realms encounter the Ferryman and wish to procure his services, one must pay a fee of exactly 2 copper coins.
The River Styx, writhes through the entire underworld. The River Styx begins in Limbo, and flows through realm, eventually arriving at the City of Penumbra, where Charon docks, and offboards the souls in his charge. From the City, The River then flows into 4 further Rivers; Acheron, Phlegethon, Cocytus and Lethe.
The City of Penumbra, referred to by some as the Gates of Hell, Penumbra is the entryway to the underworrld. From its docks, one is transported to either the 13 Hells, The Abyss, Hades, where Thanatos, the God of Death resides, or to The Celestial Heavens.
The River Acheron, The river of woe or misery, leads one to the 13 Hells.
The River Cocytus, The river of lamentation, leads one to Hades, the Land of tthe Dead, rules by Thanatos.
The River Phlegethon,The river of fire, leads one to Tartarus, The Abyss, where one will suffer for all Eternity.
The River Lethe, The river of forgetfulness, leads one to the Celestial Heavens, where one may be granted the right to join the Celestial Choir.