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Likely Sora, considering how powerful his heart has become due to the connections he's made. But it's all very debatable considering Riku's new rank, and how powerful Master Xehanort may be. Plus we have no idea how powerful characters like Yen Sid are if he even has a Keyblade.  Timelinesplitter Chaos 13:07, December 21, 2012 (UTC)

What about Aqua? Many thnk she's the most powerful one... AkaAxl 13:44, December 21, 2012 (UTC)

While that's believable, and I can see why that would be. The Keyblade is a weapon of the heart, thus depending on the strength of your heart, you would be extremely powerful. Sora gained tremendous power by travelling to other worlds and creating ties with other people and making many new friends. This makes Sora very powerful. Something that the Keyblade wielders of old never had the chance to do, I don't think. Plus, Terra was able to defeat Xehanort (using Terra's Body), just the same as Aqua was, the only thing that made Aqua a more formidable opponent, was the fact that she was taught many secrets that Terra and Ventus didn't know.  Timelinesplitter Chaos 22:29, December 21, 2012 (UTC)