Kokytos

Κωκυτός
A flowing river of eternal lamentation and woe that empties into the Void.

Spoilers
Warning, Major Series Spoilers ensue... Peruse at your own risk: ====== A New Kharon Series ====== n/a

Real World Influence
Wikipedia:Cocytus Cocytus is the river of wailing in the underworld in Greek mythology. Cocytus flows into the river Acheron, on the other side of which lies Hades, The Underworld, the mythological abode of the dead. There are five rivers encircling Hades: the Styx, Phlegethon, Lethe, Acheron and Cocytus.