I think the other HAS to be Gandalf. I REFUSE to believe he is good. I think Tolkien menat to write a epilouge showing gandalf was evil the whole time. period.
"Kill the lights, these children learn from cigarette burns, fast cars, fast women, and cheap drinks. It feels right, all these asphixiated, self medicated, take the white pill, you'll feel alright."- I'm Not Your Boyfriend Baby by 3OH!3