I never said she couldn't have the same mission, but then again that would be defeating the purpose, since Xemnas needed the released hearts to make an artificial KH. I doubt they'd use the same idea for losing the keyblade just to make the 14th member fit in the story, I find that highly unlikely, so it's not really an arguement to use on your part. :glare:
You find highly unlikely that Xemnas would be more than satisfied to get another keyblade wielder for creating the KH two time faster? Weird, from my part, I find this fit very well. And suddenly, what I said is rather an argument good to use on my part. In case you want to say this argument is still not good to use, I'll just say, as you wish, I just stay on considering more Xemnas can have keyblade wielder, more "happy" he is...
Oh, and you forgot my two others argument : she could have another mission with her keyblade, something only someone more skilled than Roxas could do.
And don't forget another argument in which, like Xemnas, she lost ability to wield it, and then, she'd have another weapon. This being said, now, try again to say that #14 is Aqua's nobody is a stupid theory in using good argument. You'll see you can't.