Wizard Gone Missing

[littlemanpoet]

The new names arrived around the time Thorin & Co. reached the Lonely Mountain--thus freeing up the name "Bladorthin" to belong to the king of the undelivered spears--and when the wizard returned to the stage he was Gandalf.

This is the anchor I have needed. It fits with what I've been struggling to say. The change in Gandalf occurs between his disappearance just before Mirkwood, and his return just before the Battle of Five Armies.

Does Rateliff's book say that "Bladorthin" is an Elvish name?

I'm not sure it matters. If I were a writer in Tolkien's place, I would want to make my wizard have a very different kind of name from my Dwarves. Bladorthin is very different; Tolkien realized later that Gandalf is also different from the other Dwarvish names, having the root "elf" in it. So in his wizard he always had an "Elvish" quality.

For Tolkien, it seems, "Elvish" meant a different kind of magic than that of the Dwarves. Yet both are perhaps Nordic/Germanic as opposed to Celtic. (Thanks for your help in clearing that up a bit, Galadriel55).