I have two major questions about Sora's ability to wield a keyblade.

 

First, we know that Sora has the ability to wield a keyblade because Ven's heart is inside him. But during the events of Kingdom Hearts, Sora unlocks his heart to free Kairi's, thus freeing Ven's heart as well. When Kairi brings Sora's heart back from the darkness, he is still able to wield a keyblade even though Ven's heart is not in him. Why?

 

Also we know that Roxas has the ability to wield a keyblade because Ven's heart went into Roxas. We also know that Xion is able to use a keyblade because she is an imperfect replica of Roxas. When Roxas absorbs Xion, he is able to wield two keyblades. If we use the same logic, should Sora not be able to wield three keyblades, his, Roxas/Ven's, and Xions?

First off, the reason why Sora was able to weild the keyblade even after turning into a Heartless and freeing Ven's Heart in the process was because his heart was strong enough for the keyblade to accept him as a true keyblade master after that whole "my friends are my power" speech. Second off, Sora got the ability to dual weild, or triple weild in this case is mainly thanks to the fact that Roxas merged back with Sora. Thus, passing on his ability to weild more than one keyblade down to Sora. But as far as we know, he can weild at least four keyblades thanks to Roxas and the fact that he holds Ven's heart inside of him.

KingdomHearts125 has it right about why Sora got his Keyblade back after his stint as a heartless.

 

As for Sora only being able to use two keyblades, the answer is that there are only two Keyblade original keyblade wielders in this equalization.

Ven has his Keyblade. Sora has his own. Both Roxas and Xion's ability are based on Ven's or Sora's ability to wields the Keyblade. So when Roxas and Xion rejoined Sora, they were not bringing any knew ability with them. Only what was already there.

First, we know that Sora has the ability to wield a keyblade because Ven's heart is inside him. But during the events of Kingdom Hearts, Sora unlocks his heart to free Kairi's, thus freeing Ven's heart as well. When Kairi brings Sora's heart back from the darkness, he is still able to wield a keyblade even though Ven's heart is not in him. Why?

Ven's heart is the reason Sora can wield two Keyblades. The other one is his own. How did he get it?

In BbS Terra choose Riku too one day become a Keyblade wielder but, during the Heartless invasion on Destiny Island, Riku turned too the darkness and the Keyblade choose Sora instead.

Well, I don't need to explain since they did already.

Xion is an imperfect replica of 'Sora' not Roxas.

The keyblade didn't per se "chose Sora (just clarifying), but then again trying to explain a lot of what happens in kh1 in the context of the other games becomes some of the most confusing stuff, so its hard to try to explain it. (My attempt to explain what happens in kh1 in the context of other games:) Sora's strength of heart and the fact that Ven's heart resided in Sora's, let Sora take the keyblade from Riku when the opportunity would arise, which we know to be when Riku reaches out to Sora that fatefull night. Later on in Hollow Bastion Riku is able to take the keyblade back because Riku's heart was stronger than Sora at that point, but when Sora gives his speech about his friends being his power, the keyblade returns to him. That speech brings up multiple points concerning its successor in coded when Sora gains the keyblade for real as well as its predecesor in bbs where Ven gives that speech: if Ven is the indirect reason Sora gave this speech, then he must have also left a lasting influence even after his heart left... but thats for another discussion. Sora gains the ability to wield (that ability specifically not being strength of heart but rather the ability from the inheritence cermony ) some time before he releases ven's heart and Riku loses that strength of heart that should have let him wield his own keyblade.

 

Roxas was obviously using Ven's keyblade and ability. Xion, being a replica of Sora, was able to use a copy of his keyblade, not truly his keyblade. When Roxas absorbed Xion, he awakened the ability to use Sora's keyblade, which Sora acquired in kh1. Then when Sora absorbs Roxas, Sora inherits that ability to wield two.

So they both have the ability to wield each others keyblades? Well that explains it, thanks.

Its because their hearts became united during the last day of summer

No. It's like you said Xion is an imperfect replica of Roxas.

no xion is an imperfect replica of sora, kupo.

Xion is an imperfect replica of 'Sora' not Roxas.

 

Sora and Roxas are the same. Xion is an imperfect replica of them both.

i thought aqua told sora to do somthing idk but what about kiri why the firetruck can she wield a keyblade

if she was literally a copy of Roxas shed look like him when complete dont you think?

 

that aside, its specifically stated shes a copy of sora.

if she was literally a copy of Roxas shed look like him when complete dont you think?

 

that aside, its specifically stated shes a copy of sora.

 

Well yeah, but Roxas and Sora are essentially the same being.

 

Well yeah, but Roxas and Sora are essentially the same being.

 

i cant help the fact that i take things literally. they may be the same but it makes sense to use the words they used, dont you think?