Fun fact for those thinking he looks like Gandalf and not knowing why: Gandalf's design is actually based on Odin (Tolkien was a huge mythology fan, specifically Norse and English). While most know Odin as the one-eyed king of the gods, he also often traveled on Earth disguised as a cloaked old man with a wide-brimmed hat
The more you know. Great info.
If your main association with Odin comes from other fantasy depictions such as the Gargoyles TV show, Final Fantasy, the Warriors Orochi franchise or games like Odin Sphere you're not used to think of him as a wizard-esque figure.
Considering it seems Luxu is the one to do it (chronologically) first the technique has to be older than that but I remember Xehanort stating in his BBS reports that transferring hearts, both their own and others, is an ability all true Keyblade Masters have access to.Will Master Odin be the one to teach Xehanort how to acquire vessels?
And besides, transferring your own heart to a vessel does not always have to mean forced possession and/or taking over a vessel that's already "occupied".