Quote Originally Posted by Sidnne
A couple of things about this in chapter 456.

http://www.onemanga.com/Naruto/456/01/
On the first page here, when Danzou is performing a jutsu, there is a four-frame focus on his hand seals in the middle of the page. That to me is significant. First, he appears to have some kind of metal contraption bolted to his arm, possibly a prosthetic. Maybe he is a cyborg?
Good catch. That's a very interesting bolt.

http://www.onemanga.com/Naruto/280/19/
http://www.onemanga.com/Naruto/281/15/

It almost looks like there is one on his right wrist in the second page, when he holds Deidara's arm. (Admittedly, that bold is not so clear)