So...it's just Xemnas armor? Why...did I see that one coming?
Anyway concerning the Xemnas being able to use a keyblade but choose not wield one is something that we won't be able to fathom until further games explain. Every notion we make has a contradiction. He was lazy =/= he didn't use it against Sora and Riku. He chose not =/= He wanted his KH completed. He didn't want to be like MX =/= He has no remorse. But what if, he could have but he didn't...what if...Riku took it? I mean hear me out. Riku dual wielded in TWTNW. Who's keyblade was the second's? Wasn't Eraqus (with Aqua). Wasn't Terra (With LS). Where would that other keyblade come from? I think Riku took Xemnas' only legitimate keyblade (MX's). But because of his memories it became that floral Destiny's Place or whatever. Unless you believe that one can duplicate the same keyblade. I mean look at it this way, did all those hearts really come from Sora, Roxas, and Xion alone? What about before then? What if Xemnas was harvesting on the side, Ansem SoD f*cks up by having Riku harbor him, and then *poof* Riku has access to said keyblade. I mean it makes more sense, to me at least, that Riku stole it.