I share my Picture of the Legends of Halo, Rook, Master Chief (CE), Master Chief (MarkVI), Noble Six.
http://www.bungie.net/Stats/Reach/FileDetails.aspx?fid=16498004&player=frogx4
I like your idea of showcasing the main characters but I feel like they should be facing more that one direction (with the exception of MC-Mk VI) and I also can’t help but notice that your background is a bit barren. Effects are really all the rage today so if you don’t perform well, your work comes off as lackluster.
Overall, like I said earlier, it is a really good concept (my favorite touch is the Jet-Pack on Rookie to simulate his backpack).