I saw these in the Artist's Gallery. My impression was this:
Duality is dinero roxors but it could still use some tweaks.
Floral Secret is okay . . . not to my taste. I also think the leaves could be smaller and there could be at least three.
Cataclysm . . . in KH, I disliked the mammoth Olympia and in KHII, I wasn't fond of the blatant Rumbling Rose. It's just M/O but I don't think bigger is better, keyblade-wise.
Have you seen my Art Challenge in the Artist's Forum? I'm going to be adding a keyblade art to the list of challenges. If you're at all interested in testing your fanart, by all means give it a try.