Meh. I'm not as convinced that Odin is a mask or mantle.
I am, but mostly because Im relatively confident he is not the original All-father.
And i don't think that Santa Claus was a naturally occurring mantle; I think it was constructed specifically for Odin to keep him involved after the handover of the Guardianship.
Im not entirely convinced any of them would qualify as "naturally occuring" with the possible exceptions of things like The Eldest, or maaaaybe the Erlking.
As for the "native santa", maybe the Kringle mantle was built to incorporate "Handsome Fellow" into itself, but I don't think there's any faith to be had from that. Not much faith in Kringle, for that matter.
You have apparently missed the Elf-on-the-shelf phenomenon
Faith does not need to be filtered through a church or holy book to be real. And Frankly, Kids do Belief better than we adults do.
And I do think that there are different entities for different pantheons. I don't think that the Hopi's Eototo Kachina is the same as Odin. Both are the father figures in their pantheons, but they're not the same. Angwusnasomtaka has some parallels to the Mothers, or Gaia if they're not her, but I don't think they're necessarily the same entities.
Qualified agreement. I dont have any reason to believe that *all* similar deities are the same entity by any means, but Im not ruling it out (on a case-by-case basis) either, given what we've been told about how Immortals fight over mantles. And in the case of the greco/roman split I think we can be confident that those were an evolution of the same entities, and evolution that continued well beyond the limits of the popular myths, given the whole Fae/Hecate link.