Phlegethon

Φλεγέθων
A fiery river of judgement encircling the gates of Styx.

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

Real World Influence
Wikipedia:Phlegethon In Greek mythology, the river Phlegethon (English translation: "flaming") was one of the five rivers in the infernal regions of the underworld, along with the rivers Styx, Lethe, Cocytus, and Acheron. Plato describes it as "a stream of fire, which coils round the earth and flows into the depths of Tartarus". It was parallel to the river Styx. It is said that the goddess Styx was in love with Phlegethon, but she was consumed by his flames and sent to Hades. Eventually, when Hades allowed her river to flow through, they reunited. It is also said that when demons pour it down the throats of the damned, it mended their broken bodies, causing indescribable pain whilst healing them.