Board Thread:General Discussion/@comment-99.114.158.21-20130924002013/@comment-10321484-20131009194806

1. That feature isn't built into the game. Good luck displaying a robotic arm on a Halo engine without utilizing CGI of some sort.

2. Most modern prosthetic limbs are modeled to be inconspicuous. It could always be a replacement arm that prevents him from looking like a Transformer, so he's not viewed as different than everybody else.

Again, it is just an idea and something I noticed. It is also very likely that he's just some new character, but either way, nothing is confirmed at the moment.