Repliku wasn't Riku's nobody, and he had his very own memories until they erased them and put false ones instead. And that does not prove anything.
And no matter how much I hate to put Days as an example, I have to, it's canon after all.
Xion's fight with Xigbar kinda proves that Ven's Heart is inside of Roxas, why? Because when Xigbar looked at Xion's face he saw Ven, and Roxas is the one feeding emotions and memories into Xion. Xion adoptates the face of someone that is connected to Sora or Roxas and that preson that is looking at her has interacted with him the past (Axel sees no one until he meets Namine), so when Xigbar looks at her and sees Ven, it means that Roxas (Xion's source of memories) has interacted with Ven in the past, but how? Roxas was born less than a year ago, and Ven is "out of the picture" a lot of years ago, bit Xigbar stil sees Ven's face in Xion's, so this could only mean that Roxas holds part on Ven inside of him.
And Namine having emotions doesn't prove that she has Ven's heart, it doesn't even prove ANYTHING AT ALL, you aren't even sure if she had emotions, and if she had they could've been fake. Axel cried when he said goodbye to Roxas, and that doesn't make him have emotions, nor a heart of his own.
And better yet, at the almost-end of KH2, Namine had to fuse with Kairi in order to be complete, if she had Ven's heart, why did she do this? She is made of Sora's body and soul after all, and if she had Ven's heart, then her whole being would be Sora's property, not Kairi's, and yet we see her fuse with Kairi, I wonder why.
