Axel, Sora, Donald, and Goofy probably could have killed them all pretty fast. When Sora did the thousand Heartless battle, it was just him, and he fought Heartless stronger than Shadows, which are the easiest. But it was only a thousand Dusks, the easiest Nobodies and there were four fairly strong characters. Also, where was King Mickey during all of this? Didn't he enter the portal with every Sora and co. and didn't he reappear after the cutscene ended? I might be wrong, seeing as I haven't played KHII in awhile, but I could have sworn Mickey entered the portal.
I doubt it's that important that he grew so much. The creators were probably just trying to make him look cooler. But you never know, you might be onto something.:star-wars-smiley-02
I was playing around in TWTNW and I had Riku in my party. I noticed two things about Riku's Keyblade, Way to the Dawn:
1)It had a striking similarity to his sword from Kingdom Hearts 1 and CoM. If you don't believe me take a look here: http://images.wikia.com/kingdomhearts/images/d/d4/SoulEater.jpg (soul eater) and here: http://images.wiki.wegame.com/i/371XoPGt.png (way to the dawn)
2)Way to the Dawn's keychain is a heartless symbol. This made me wonder if Way to the Dawn is the Heartless version of Soul Eater. Does that mean that there is a Nobody version of Soul Eater? And that made me wonder if all weapons, Keyblades included, have a Heartless and Nobody version too. I could just be grasping at straws here, but tell me what you think.
P.S. Sorry about the title. It was supposed to say can Keyblades have Heartless/Nobodies?
