A few months ago, while deconstructing my Voyager Fallen, I happened upon an interesting piece. the wrist swivel is pinned into the translucent red plate on his forearm by way of a moderately sized pin/post/armature. This, when the arm is unscrewed, comes out to be a piece resembling a red axe. With some minor modification, this could potentially become a decent weapon for any deluxe Optimus. I say deluxe on account that the piece is still rather short, having come from The Fallen's arm. I hope that this is at least informative if not beneficial.