Given that Kingdom Hearts is pure light that has been locked away for a really long time, and that Xehanort is going to try and open it up, isn't he essentially defeating himself in his notion of "balance" by bringing back the one thing that emanates more light than anything else? 

i'm still not even getting what exactly kingdom hearts is to be honest....

i mean i've heard that the final battle in KH2 took place in some way inside Kingdom Hearts but how does that even work? it feels like Kingdom Hearts as a plot point is being kept vague enough to fill whatever need it has to.

Pretty sure giving the name "Kingdom Hearts" to an actual thing in-game was an afterthought and boy is that really showing here in the end game

Last time Kingdom Hearts was opened the world was covered in Darkness. It's not really Kingdom Hearts he's after, it's the Darkness that would be brought about by another Keyblade War.

i'm still not even getting what exactly kingdom hearts is to be honest....i mean i've heard that the final battle in KH2 took place in some way inside Kingdom Hearts but how does that even work? it feels like Kingdom Hearts as a plot point is being kept vague enough to fill whatever need it has to.Pretty sure giving the name "Kingdom Hearts" to an actual thing in-game was an afterthought and boy is that really showing here in the end game

I think Kingdom Hearts is the source of all power and knowledge, but don't hold me to that.In Kingdom Hearts II, the Kingdom Hearts which Sora fought in was for man, and was artificially built if I recall correctly, but again don't hold me to that.As I mentioned above, I believe Xehanort wants all knowledge and power, which we can assume would be held by Darkness possibly, or if he were to be unlucky the source of power would be light.

Edited September 19, 201510 yr by Unknown Figure

Ben Dinskin stated in his Reddit that Xehanort may want to open Kingdom Hearts for a reason far beyond what he's already stated. He may have initially wanted to rescue the third friend in the trio that is already in Kingdom Hearts but through his hunger for power and the need to balance light and darkness, he lost his inital reasoning for opening Kingdom Hearts.

originaly xehanort wanted to restore balence the the worlds using kingdom hearts but it seems his goals have changed, according to this secret report:

 

Day 358: Goals Author: Xemnas With luck, we can bring Roxas back into our fold, but even if Sora should awaken, as the hero of the Keyblade, he is bound to keep unlocking hearts. If he should come to target us, we need simply subdue him and use his powers ourselves once more. I must become one with Kingdom Hearts. I will become a higher existence. All of my true ambitions begin there.  

 

it seems that xemnas plans to become a god

Edited September 19, 201510 yr by liamaru

I believe we have only seen the true Kingdom Hearts once in the series, in BBS. The Kingdom Hearts in KH2 was artificial. I think Xehanort is aiming for the darkness that will come from a Keyblade War and he wants the power that comes with Kingdom Hearts

That's what happens when you keep retconning everything to make your Villain Sue look all-powerful---sooner or later, you lose track of character consistency.

originaly xehanort wanted to restore balence the the worlds using kingdom hearts but it seems his goals have changed, according to this secret report:

 

Day 358: Goals Author: Xemnas With luck, we can bring Roxas back into our fold, but even if Sora should awaken, as the hero of the Keyblade, he is bound to keep unlocking hearts. If he should come to target us, we need simply subdue him and use his powers ourselves once more. I must become one with Kingdom Hearts. I will become a higher existence. All of my true ambitions begin there.

 

it seems that xemnas plans to become a god

 

His true ambitions may be more sentimental and complex than just "being god-like!".

It's simple, Xehanort is so curious that he wants to become a God. Alternatively, Xehanort is unsatisfied with the way the world(s) work, so he wants to reshape them in his own image by combining them all together into a "superworld". In short, he's like Hitler or Stalin or even Attila the Hun, they wanted one goal in life: to become extremely powerful and reshape the world to meet their needs.

Master Xehanort wants the X-blade to himself so he can gain control of Kingdom Hearts and obtain power. Even if the Keyblade War were to begin again, he would have all the control in the world to see what he wants and when and everything will be under his rule.