In this thread, a person more powerful than every FF character

[PuPu]

However Cloud's sword is (for all we know) just a normal sword

And Sora's keyblade, for all we know, has the ability to release hearts. There's nothing which suggests that Keyblades give powers to their wielders either, and there's nothing which suggests that the Keyblade gave Sora the ability to leap hundreds of feet in the air.

If we were to give Cloud and Sora struggle bats, remove any magical clothing/accesories/materia. Sora would be significantly weakened.

Not anymore than Cloud would, since if you take away everything that supposedly makes them both superhuman...then they would both be significantly weakened.

No but they are still operating by the same universe/rules. Different games opperate under different rules.

Which hardly matters, since power works in practically the same way in all games. Or at least, in these games. They may have different forms of power, but they still have power, nonetheless.

What you are claiming is that the worlds greatest boxer is a better fighter than the worlds greatest taekwando master because the worlds greatest boxer defeat the taekwando master in a boxing match.

I...don't think I was claiming this, but even if I was, the statement in this quote is still true.

EDIT: Actually...I'm not seeing at all how this analogy came from:

Xemnas being the more powerful entity in a multiverse that is KH vs Sephiroth being the most powerful entity in the planet of FF7.

To fix your analogy, it's more like:

Xemnas is a better fighter than Sephiroth because Xemnas is Russia's best boxer while Sephiroth is only my local town's best taekwando master. Emphasis on Xemnas being the best fighter, and nothing specific such as the better boxer or taekwando master, though the former is probably true. I'm not saying that Xemnas has more control over Lifestream than Seph does and I'm not saying that Seph has more control over KH than Xemnas. At least, I think this is what your analogy is trying to imply. Sure, Lifestream and KH are different forms of power, but still power nonetheless.