Other related deities and entities related with this deity.
The biggest relation to another deity that Odin has would be to Loki. While only mentioned in two stanzas, it is said that Odin and Loki are blood-brothers and that Odin would not accept drink unless it was offered to Loki as well. This always stuck out to me, even before I fully dove into Asatru and Heathenism. Now as I wander through posts about the deities and see huge arguments over the exclusion or inclusion of Loki I wonder what others think of the relationship. Do these people disregard the bond the two have? Do people only see the bad Loki will do/has done? I will not deny that there is some negative things in the tales of Loki but he did much good. I think the reason why everyone is so upset with Loki is Baldr's death and the coming of Ragnarok. If it wasn't for Loki, none of it would have happened. In my mind, though, there is no positive without negative and vice-versa.
Then there is Mimir. He is the wisest of the Aesir and was given to the Vanir as a hostage during their war. Unfortunately he was beheaded and his head was returned to the Aesir. It was Odin who preserved Mimir's head and conversed with him. Mimir gave Odin his wisdom after the Allfather sacrificed his eye.
As for other entities, one could point to the Ravens of Odin, his wolves, Sleipnir, and even Fenrir, who will kill Odin during Ragnarok. While each of them play specific parts, for some reason I am not urged to describe them. Mimir and Loki are more prevalent on my mind. Perhaps I'll go into further details on these creatures at a later date.