I noticed that, while some keyblades look thin and bladelike, the Kindgom Key (mah favorite, btw) is dull and rounded. Sure, the magical awesomeness kills the Heartless, but what will that do to a human? Bruise them?
Keyblades Aren't Sharp
Roxas swung his keyblade expertly, slashing through the Heartless without so much as blinking. It was like he'd been doing this for years, when in reality he'd only just joined the Organization and gotten used to using his keyblade. The little swordsman.
No, Axel reminded himself wryly. He's been using this keyblade for over a year, as Sora.
"The keyblade is such a weird weapon." Roxas said suddenly, surprising him. "I mean, it's not even sharp. How's it going to injure anyone?" He looked at Axel expectantly. The redhead shrugged, grinning.
"Well, kid, it's bound to leave a nasty bruise."
Giant keys are pretty cool, but I'd still rather thwack people with a giant banana :D Go Saix!