That is one awesome costume. I think ones an elite...? I have no idea. Feel free to fill me in on what exactly they are.
On the right:
If you are the Cosplayers, please comment and tell me, so I can give you credit.
And yes, she gave me permission to post these photos, as she does not use her dA very much.
Taken at Anime Expo 2011, held at the LA Convention Center