Less is known about the role of Odin as receiver of the dead among the more southern Germanic tribes. The Roman historian Tacitus probably refers to Odin when he talks of Mercury. The reason is that, like Mercury, Odin was regarded as Psychopompos, "the leader of souls".Odin as a leader of the souls is reflected in the tale of the Pied Piper (scroll to page 33). And here is a lengthy article on the connection between Odin and Hermes (Mercurius aka "Mercury").
Julius Caesar states in De Bello Gallico 6.17.1 that for the Gauls the worship of Mercury was the most important, or perhaps most widespread, out of all the gods.
Paulus Diaconus (or Paul the Deacon), writing in the late 8th century, tells that Odin (Guodan) was the chief god of the Langobards and, like earlier southern sources, he identifies Odin with Mercury (History of the Langobards, I:9). Because of this identification, Paulus adds that the god Guodan, "although held to exist [by Germanic peoples], it was not around this time, but long ago, and not in Germania, but in Greece" where the god originated. Wace also identifies Wotan with Mercury. Viktor Rydberg, in his work on Teutonic Mythology, draws a number of other parallels between Odin and Mercury, such as the fact that they were both responsible for bringing poetry to mortals.
Similarly, Ammianus Marcellinus most likely references Odin and Thor in his history of the later Roman Empire as Mercury and Mars, respectively, though a direct association is not made. This, however, underlines a particular problem concerning ancient Greek and Roman sources. Historians from both cultures, during all periods, believed the deities of foreign cultures to merely be their own gods under different names (see interpretatio graeca). Such an example may be found in Herodotus' association of an Egyptian Ram-headed god (most probably Amun) with Zeus. Later, Medieval historians followed the older tradition and likewise made such associations. However, there is no historical evidence to suggest that these are valid connections and as such they should not be taken as historical fact.
Odin experienced two shamanic initiations. In one, he sacrificed one of his own eyes for the privilege of drinking from the Well guarded by the wise giant Mimir, in order to obtain awareness of the past--the name "Mimir" is related our word "memory"--and to acquire non- linear knowledge and intuition. His physical eyesight was partially sacrificed for another type of Sight or heightened awareness. Norse mythology has another Well, belonging to Urd, the first of the three Norse Fates, who rules the past. As Ralph Metzner states in his book The Well of Remembrance (Boston, MA: Shambala, 1994, p. 218), some critics believe that the two wells may have been versions of the same story. "Urd" means fate or destiny in old Norse, and Odin acquires knowledge of his essence, of the patterns that fate and destiny weave for gods and mortals alike, by drinking from this well.The symbol of Odin was the Valknot, which represented the 9 worlds of the universe. Of course any three points not in a straight line can form a triangle, but this shows the power and symbolism inherent in triangles.
The second shamanic initiation and sacrifice occurred when Odin hung himself on the world axle-tree Yggdrasil that connects the nine worlds, in order to attain knowledge of the Runes. Human sacrifices to the Norse gods were often hung on trees. During this initiation, Odin makes a sacrificial offering of himself to himself, while in shamanic folklore, a tree often symbolizes a ladder to another world or state of consciousness. Used as the alphabet in some Norse countries until roughly as late as 1000 CE, the Runes were more than just letters. They were an oracle, and each symbol had a divinatory meaning. (For more on the Runes, a good place to start is Edred Thorsson's Runelore: A Handbook of Esoteric Runology, New York: Weiser, 1987).
Classical Mercury and Norse Odin both rule writing--but the Runes were invested with the power and numinosity of Logos in the ancient Northern European world, and they were won with suffering. In both of these initiation tales, knowledge carries a price. As C.G. Jung wrote, "There is no coming to consciousness without pain." Not the coming to this sort of non- ordinary consciousness. Here, Odin is a far cry from Hellenistic Mercury, who was more a bearer of other's messages than a seeker after inner truth.
The search for wisdom took Odin down other difficult roads: the god was a psychopomp, a guide of souls. Here he shows a much closer parallel to classical Mercury, who escorted Persephone back from the underworld. Half of those who perish honorably in battle belong to Odin and travel to his hall after their death, while his ravens are traditionally birds of the dead. Yet Odin was also a necromancer, one who attains magical knowledge by conversing with the departed. When Odin's son Baldur begins having nightmares about his own demise, Odin descends to the underworld to learn Baldur's fate, where he raises the ghost of a sorceress to question her. He travels there on his eight-legged horse, which some scholars have seen as a symbolic coffin carried by four people. Odin also frequents hangings in order to communicate with the spirit of the victim on its way to the next world.
Death is, among other things, a transition from one state of awareness to another. Besides literal death of the physical body, we can also see these attributes of Odin as related to the self-knowledge that may spring from a psychological death: the death of a defense or a denial, or the ending of a certain phase or stage of your life. Such potentially transformative self-knowledge is seldom won without facing the underworld. Here, Odin is involved with profound psychological work, what we may call "soul retrieval."
Both Odin and the fast-talking and light-fingered Mercury show elements of the Trickster archetype. The more famous Norse trickster, the fiery demigod Loki, is Odin's foster brother, perhaps a kind of not fully acknowledged sibling--the sort of secretive brotherly rapport that might exist between two tricksters. Odin and Loki are both wily characters, shapeshifters; while among Odin's many names are the Changing One, the Twofold One and the Hidden One. Not only is Odin's appearance unpredictable as he wanders the mortal realm in various disguises, but his gifts are unreliable. Odin's berserker frenzy may abandon a warrior in the midst of battle. Berserkers themselves were thought to be shapeshifters, a kind of were-bear--the name means "bear-shirt"--while other followers of Odin were hunters said to assume the form of a wolf. Besides ravens, wolves are Odin's other animal ally--even his non-human form is elusive.
For more of the connections between Odin, Horus and ultimately Dajjal, check out these posts, and these posts for Hermes.