Kingdom Hearts II Which Kingdom Hearts is Stronger?

In Kingdom Hearts, "Ansem" use the princesses of Hearts to open the keyhole to End of the World and goes through the passage of the remnants of Destiny Islands to Kingdom Hearts the source of all hearts. (If anyone can answer this question clearly it would be nice, why is it that when Sora seals Kingdom Hearts do the hearts of the worlds return, I think its because they seal the darkness of Kingdom Hearts and thus the Hearts are freed)

In Kingdom Hearts II Xemnas and his Organization XIII create their own Kingdom Hearts by collecting all the hearts that the heartless once carried.

Which Kingdom Hearts was more powerful?

 

I assume its whichever one had the most amount of hearts built up inside it. No idea which one that was

 

Kinda depends on how powerful the heart of the princess of herart's were.

 

I think it is the one made by the Princesses of Heart.They're hearts are stronger but it can also be Xemnas' because it is made of more hearts.