Odin

Odin is the chief deity of Norse mythology and leader of the Gods of Asgard. He wields the legendary lance Gungnir.

Appearance
An elderly man with long, grey hair and a matching beard. He wears an eyepatch over his left eye.

Personality
Despite being a God, Odin is very perverted, harrassing young women and going to "Oppai Clubs" for fun. He also has a tendency to make fun of his bodyguard, Rossweisse, calling her "the Valkyrie whose age is equal to the number of years without a boyfriend". Odin, however, is not completely irresponsible, proven when he felt like he brought trouble to Issei and his friends when Loki attacked. He even broke the rules of his religion and came to the outside world in hopes that the young ones in his religion will ponder their future and prepare a new path for the religion and for themselves.

History
Not much is shown of Odin's past except for the fact that he is one of the Gods that have been active since ancient times and gave away his left eye to the Mímisbrunnr. He also took Rossweisse as his bodyguard some time before the start of the series.

Birth of the Breast Dragon Emperor
Odin first appears near the end of Volume 4, commenting on the death of the God from the Bible and how the Christian religion became a children's playground (referring to Sirzechs, Azazel, and Michael) but claims that it is interesting to see what these youngsters can do without God.

He later watches the Rating Game between Rias and Sona in Volume 5 and complimented Saji for his determination which allowed his team to defeat Issei.

In Volume 6, Odin, after breaking through the barrier set up by the Dimension Lost, helped the Gremory team by disposing of the Devils of the Old Satan Faction.

The Heroic Oppai Dragon
In Volume 7, Odin, with Rossweisse and Baraqiel as his bodyguards, encounters Issei and Akeno during their date. He later goes into the Hyoudou Residence announcing his visit to Japan, telling Azazel that he had "trouble at home" and about the increasing numbers of Balance Breaker users in the Khaos Brigade, before leaving with Azazel to go to an Oppai Club. When Loki came to Issei's town, condemning Odin for falling so low to consort with other mythological systems, Odin replies by saying that he enjoys talking to Sirzechs and Azazel more than he does with Loki and wants learn more about the Japanese Shinto, and that the Japanese Shinto are also interested in their Yggdrasil, wanting both sides to negotiate peacefully and start cultural interchange. He later has a private conversation with Azazel, stating that he feels sorry for bringing trouble to the Gremory and Vali Teams, hoping that his actions of coming to the outside world will open a new future for the youngsters in his religion. After the battle against Loki, Odin leaves Rossweisse in Japan.

He reappears in Volume 10 during Rias and Sairaorg's Rating Game with a new female bodyguard, running away at the sight of an angry Rossweisse who began to chase him.

The Legend of Oppai Dragon and his Lively Companions
In Volume 16, It is stated by Azazel that Odin takes Vali as his adopted son in order to be pardoned for his, and the rest of Vali Team for their crimes and their affiliation with Khaos Brigade

Powers & Abilities
Immense Strength: Being the chief deity of Norse mythology, Odin is extremely powerful but he claimed that he was much weaker than when he was younger. He easily disposes hundreds of members of the Old Satan Faction that consist of High and Middle-Class Devils with a single strike of his lance, Gungnir.

Magic Eye: Odin's left eye, which he gave away to the Mímisbrunnr, gave Odin the ability to become familiar with many types of demonic powers, magics, and other spells.

Equipment
Gungnir: Odin's legendary spear, an extremely powerful spear that Odin wields in battle. Odin was able to easily disposed of hundreds of High and Middle-class Devils with a single strike of this spear.

Slepnir: He also rides his eight-legged horse, Sleipnir, as a means of transportation, often having it pull a large carriage for him to ride in.

Trivia

 * Odin is one of the few Gods who actually belives in reconciliation between the different factions, along with Zeus.
 * Odin is one of the two Gods that have appeared in two story arcs, the other being Indra.