I call this guy Romeo. Romeo was my least favorite character in Halo 3: ODST. Primarily, this dislike was because I simply am not very good with the sniper rifle, which is his main weapon. Not to mention that the whole level you control him is built around distant enemies with Beam Rifles. Plus, most of his dialogue was annoying.
In any case, he makes a good minifig. He comes equipped with a sniper rifle, which has not been released previously (I think), as well as my favorite: the MA5C assault rifle. For me, this rifle is so iconic that it galls me that every HaloBloks set does not include it. All the other plusses and minuses from the previous two figures apply here. The stand is even more important for Romeo than for Dutch or the Rookie, though, as he will not stand up withoug it, if he is holding the sniper rifle.
My wife wanted me to do this in the order of Red, Green, Blue, because I don't have a white armored guy, but I figured no one would catch it unless I mentioned that I did it, since I don't think anyone's flag is red, green, blue. Whatever.