Phlegethon

The Styx is one. It could make mortals immortal. Sorry, don't know any others.

Styx, Acheron, Cocytus, Phlegethon and Lethe are the five rivers of the underworld.

The cast of Phlegethon - 2011 includes: Andrey Gromov as One Sewing Fishes Alexander Kheitkov as One Listening a Gramophone Natalya Kudryashova as One Fallen in the Wood Mikhail Malkin as One Drawing Sergey Vatagin as One Making a Bomb

There are five rivers: Styx, Lethe, Acheron, Cocytus, and Phlegethon. They symbolized hate, oblivion, sorrow, lamentation, and fire respectively.

the Acheron (river of woe), the Cocytus (river of lamentation), the Phlegethon (river of fire), the Styc (river of unbreakable oath by which the gods took vows), and the Lethe (river of forgetfulness).