The Masamune does not increase with each appearance guys, it just fluctuates all over the place. Just like a real penis. It ran the gamut of shorter than and longer than his FF7 art in Advent Children. It was at its shortest in Crisis Core. It was longer in Kingdom Hearts. It's longest is, apparently, Dissidia 012.
And I don't like, by the way, that all the character's weapons are suddenly Keyblades in Dissidia that are summoned from somewhere on command. I understand that in the games they only showed up when convenient, but that was a graphical thing. FFXIII, for example, was good at showing that characters are wearing them at all times (Only Hope's vanished). Honestly, that was part of what made the Keyblade cool, you could never technically be disarmed. But now even completely nonmagical weapons are shown to do that in Dissidia. How hard would it be for the Buster Sword to always be on Cloud's back?
It's a little thing I know, but it bugged me. Almost as much as the fact that Cloud stows the Buster Sword wrong, which I suppose would annoy me more if his weapon were always there...so I don't know.