I was thinking something. Ventus became one with Sora's heart, which is why he looks like Roxas. However, I believed that it was Ventus' heart that makes Sora's heart special, so if, say, the part of healing Ventus is restoring his heart into his heart, would Roxas cease to exist?

In my opnion maybe,Roxas was Ven,but with no memories,maybe he wasn't a nobody,he could have Ven's heart.Just my opnion

That... is actually a good opinion. O.o

very well said, i mean, roxas cease to exist?

like its really true, sora will only live because of ventus, and namine will destroy both hearts. then darkness might control

Roxas fought very hard to be his own person...its only fitting he becomes one so no, I dont think Roxas will cease to exsist.

I think Roxas will cease to exist. He'll be in limbo probably...he has a strong "Heart" so to say. He fought hard to exist so I don't think he'll be leaving anytime soon. Blah.

Roxas will be just fine.

when he was created, he had nowhere to go so he went inside Ven's body.

But in KH3, Sora is returning Ven's heart.

Roxas may have a slightly altered appearance.