So do you think it is Gandalf, Sauron, or somebody else? Gandalf would befriend harfoots, but would not kill fireflies. Sauron would kill fireflies, but would not befriend harfoots. And either one would offend canon (especially Gandalf) although that clearly is not stopping them. Saruman? Bombadil?
I think the Meteor Man leads the Harfoots to the Shire. I also think they are showing us the creation of Mordor at the South Lands. I was thinking that Halbrand was the reverse of Aragorn by failing his kingdom seeing as how it becomes Mordor. Also about Hal,
Apparently a leak came out and said that he's Sauron which would explain the character
In total, I think we're getting the creation of rings, creation of the shire, and creation of Mordor.