Medea - In Greek mythology, Medea is the daughter of King Aeëtes of Colchis, a niece of Circe and the granddaughter of the sun god Helios. Medea figures in the myth of Jason and the Argonauts, appearing in Hesiod's Theogony around 700 BC,but best known from Euripides's tragedy Medea and Apollonius of Rhodes' epic Argonautica. Medea is known in most stories as a sorceress and is often depicted as a priestess of the goddess Hecate.
Sokar is the god of fertility and the patron saint of the dead. The center of his cult is Memphis. Sokar's epithet is "from Ra-Setau", that is, from the kingdom of the dead.
I will use only one picture of Acheron for you to imagine the 5 grand rivers of Hades kingdom – Lethe, Acheron, Styx, Phlegethon & Cocytus. The picture had been drowned by Alexander Dmitrievich Litovchenko, 1861
Fafnir - In Norse mythology, or Frænir (if you like) is a son of the dwarf king Hreidmar and brother of Regin, Ótr, Lyngheiðr, and Lofnheiðr. After being affected by the curse of Andvari's ring and gold, Fafnir became a dragon and was slain by Sigurd.