I like Kingdom Hearts deeply. I played KH1 & KH2 as a young teen, before learning of the other games. I later watched many recaps of KH, played Dream Drop Distance on 3DS, & found it all joyous. I really do like the series, in all its cheesyness, its heartwarmingness, seeing Sora & everyone happy & full of anguish.
But perhaps I shouldn't be saying what could be called an appeal to emotion/strawman. The point of saying that is to establish that I really do like Kingdom Hearts. But supporting a series doesn't mean I'll support a revision if it doesn't seem reasonable.
On one side, I can understand being opposed to Ant saying simply "I agree with Dark649" or the like, as he does that often, & I'm skeptical of that & FRA; I don't like claiming you support a side without explaining why you support it. Establish your reasons, your case. I feel this way about anyone in any debate. (Nothing personal, Antvasima.) This is mostly my emotions talking, but someone saying they agree with what someone said earlier without establishing why or how doesn't give me confidence that they've considered the debate.
BUT ANYWAY....
I have my doubts about Sora scaling to the full power of Kingdom Hearts. Yes, the X-Blade has been called the protector & counterpart to Kingdom Hearts. But the counterpart in what manner? How does it correspond? Is it a form of power from Hearts (It was formed by clashing hearts of Light & Darkness.) that manifests touchably to mankind, unlike the seemingly untouchable Kingdom Hearts?
Is it that it is the weaponized form of Kingdom Hearts? The united and organized form of it? And how does it protect? By being required to summon Kingdom Hearts? By judging the user?
The X-Blade being comparable to the entirety of KH is questionable, IMHO, & a lot of is left vague.
Then there's the issue of is Sora actually powerful enough.
He did stagger slightly, I recall... and then immediately got knocked back & was pretty much down. But I don't think holding it back for a moment is enough, not merely because he got knocked out. SURE, he did send it back with the help of Donald & Goofy....
But it's also dubious to say that Sora always has the power of his friends with him, as was said earlier in this thread. Following Sora being knocked down, he specifically has to call on the power of his bonds; If he has to call on it, it's not always active.
Also, it was mentioned that Sora would have to go & gain new power due to what he lost from nearly succumbing to darkness at the end of DDD. And I'm pretty sure Yen Sid knew part of how Sora would gain power would be forming bonds; Going out into worlds & making friends.
If Sora gets power from all the bonds he forges, then he certainly doesn't have the same level of Friendship Power for most of the times.
THEN we run into the issue of Sora overpowering KH's power DOESN'T MAKE SENSE.
At the Keyblade Graveyard, he & all the other Guardians of Light were defeated by the Demon Tide, seemingly amped, & which has taken on Aqua, & later Aqua & Mickey, in the Realm of Darkness. Even in Twilight Town, where it shouldn't be amped by being in the Realm of Darkness, it still managed to fight against Sora and then come back for more.
It is somewhat unreasonable it defeated ALL of them, but amped with so many more Heartless than usual, it could definitely prove a match. And Sora DID die. His body was gone, he was only holding on to any kind of form because of Kairi -This was established repeatedly- & practically was dead.
Reality got overwritten because of Sora's abuse of the Power of Waking, & that's part of why Sora & company came back, but the fact remains they did lose once.
When Sora & company come back & fight the even stronger Demon Tide, they don't defeat it on their own; Sora gets help from Ephemera & all the Keyblades of the Keyblade Graveyard.
So it was stronger than before, & needed all the Keyblades of the Keyblade Graveyard, plus Sora, to be defeated.
But even if we assume a base of maximum Large Star Level, & then assume that it needed as many Keyblade Wielders as there are people on Earth.... Roughly, 7.4 billion... Heck, even the total number of people who have EVER lived on Earth AT ALL, now or before, about 100 Billion....
Well, to go from maximum High 4-C (Large Star Level, what most of the KH cast is rated at.) to maximum 4-B (AKA, baseline 4-A.), you need to get roughly 881.86 BILLION times stronger.
Getting to maximum 3-C needs 198.37 million times THAT power, & getting to maximum 3-B needs roughly 1.04x10^23 times THAT much power.
If Sora lost to the Demon Tide once, and needed help to finish it off from countless Keyblades (Including those of the Foretellers.), & it's still WELL IN EXCESS of BILLIONS of times weaker than 3-A? I'm skeptical.
And not only that. Consider what happens BEFORE Sora has to call on the power of his bonds of friendship: He shoots Xehanort with a beam from his Keyblade and Xehanort EFFORTLESSLY blocks it. Not even with the X-Blade. Just a barrier. Doesn't even make it to Xehanort's lightly raised hand.
& in fact, the background scenery is notable at this time. We see Xehanort raise the X-Blade, & Kingdom Hearts's light seems to fade, disappearing, becoming completely dark/purple, & Xehanort, glowing with yellow light like that of Kingdom Hearts, fires a purple beam, seemingly one of darkness.
Sora barely held up against the beam for any time at all. About 3 seconds, before being knocked back, & out. Do we scale someone to something that knocks them out, considering that's typically a lose condition?
So, that background scenery: We can still see Kingdom Hearts is still there, just dark. Given that, I doubt Xehanort used the full power of Kingdom Hearts.
Sora overpowers Xehanort with Trinity. With the power of his friends. I don't do that, & it looked cool.
But when Sora has lost against something weaker, needed help to beat it, & got his attack effortlessly blocked, & was then knocked out with little to no resistance?
And Kingdom Hearts didn't even wipe out the universe, which was supposed to be the whole basis of it being 3-A in the first place.
If it never did that, & it's fully in tact other than being mostly darkness (Logical, as Hearts in KH naturally contain both Light & Darkness, & not even in equal balance, typically.) even when Xehanort channels its power into a beam, then KH's full power definitely wasn't used.
He didn't tank KH's action that would supposedly be 3-A, nor did Xehanort, & in fact, he was beaten, WITHOUT EFFORT by what was likely a small portion of KH's power.
Considering that AND that a lot of the calcs for KH put it into Tier 4, this seems like an outlier to me. Mathematically, it's WAY beyond his current level, & the level of stuff Sora's had difficulty with (Demon Tide, Twilight Xemnas, etc.) & I don't think I'm willing to support this as a basis for an upgrade, cool as it could be.