well I imagine final fantasy worlds are also A-okay. Also we're apparently not sticking to much to cannon concerning how our characters got our keyblades, cause in Birth By Sleep they established how you get a keyblade (You have to have the right kind of heart and touch a keyblade, unless you're Sora who has a special case...trying to be vague for spoiler reasons,) So unless we get told otherwise, I guess how we get our keyblades is up to us.