Been gone for a couple weeks.... as for the nameless things under the mountains, I think that this is a bit of Tolkien having Frodo write like Bilbo. Bilbo is much more of a poet than Frodo and he revels in the wonder of Middle-earth and promotes is inscrutability to the hobbits. There are only a few moments of The Lord of the Rings when a hobbit is not present. The story is told from their perspective... and I assume that comments about older things than Sauron are Gandalf's way of saying, "This is dangerous and beyond your understanding. I love you, but it would be best if hobbits hold this as a terrifying superstition and never pursue it." I find this out of character for Frodo's writing. He was not trying to write a fairy tale or a fantastic adventure for young hobbits. Frodo's purpose was to set down as true an account as he could. Considering the dangers of the Old Forest, the Dead Marshes, Dunland, Mordor, and knowing the terrors of the Barrow Downs, Dol Guldur, Minas Ithil, and Barad-dur, I find it peculiar how Gandalf does not open up about the nameless creatures. But then I also know that Tolkien did not want to fully explain everything. The man loved enigmas.... in order to keep that sense of wonder and mystery.
Anyway... I know nothing about the Aztec pantheon. I suppose the jobs (areas of expertise) of the Valar are fairly applicable to all pantheons. I suppose that one of them had the exact name as one of the Valar. That's not a guess, just thinking.
