>>3128792The "Odin drank Semen from dead bodies" thing is entirely made up and is literally never mentioned in any Eddas or Sagas, I hate how people still actually believe that because of word of mouth. Odin also never "turned into a woman", the closest equivalent would be Loki's shapeshifting in multiple stories where he becomes a woman (albeit not a real one OHNONONONONO NOT LIKE THIS). Loki is the god of Mischief and Chaos, and is essentially meant to represent what happens when you abandon family values. He is literally the spritual embodiment of trannies and why they're evil.
As for "how long we've known about him" is very unknown since the Germanic faith's teachings were often taught orally though poems and songs. The current earliest note we have of the Germanic Gods that is documented is from the 1st century by the Roman historian Tacitus who referred to the god as "Mercury" however this is because of a process called "Interpretatia Romano" in which Romans would identify non-roman gods by essentially equating them to Roman ones. It's safe to assume that this "Mercury" is Odin however, due to them being the most similar comparison. He also referred to another god as "Hercules" which is likely referencing Thor, as another example.
The current oldest physical piece mentioning him by name is a Golden Swastika Medallion from Denmark that was uncovered in 2020 reading "He is Odin's Man"
The truth is we simply don't know how far back Odin's origins go back because the traditions and practices were done through rituals and poems, not on books (since they didn't have them during that time period), and a lot of what did exist was destroyed by the Christians during Christianization.