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.