It seems clear to me that Ansem SoD is the only Heartless we know of that has an actual body, cognitive thoughts, and drive. In other words, he was almost a being. Now this might be clear to someone else, but it seems like Ansem SoD uses the older version of the young Master Xehnort's body. We see that Riku uses this form, and here it is most clear. This is the older version of this
So, we know that Ansem SoD is born of Master Xehanort's Heart. So why is this the only Heartless we've seen with an actual body? All of the other Org. 13 Apprentices' Heartless have yet to be seen, but is that the only reason we haven't seen any other Heartless that use a body?
So, we know that Ansem SoD is born of Master Xehanort's Heart. So why is this the only Heartless we've seen with an actual body? All of the other Org. 13 Apprentices' Heartless have yet to be seen, but is that the only reason we haven't seen any other Heartless that use a body?