>>2115386I will readily concede that the way Rei tend to be portrayed in doujin content is far from what would be considered Canon. However, another angle to consider, each entity from the Reiquarium known as Ayanami Rei may house the same soul, moved like the contents of a container between mortal shells, but each entity known as Ayanami Rei is a different entity with the capability for self-determination. Considering who we are is shaped by the experiences we have during our lives, and since each Clone is going to have different experiences, it wouldn't be too far a stretch to assume that, given enough clones, eventually you'd start to see personality become different in each clone. A simplistic way of putting is would be to consider that there could easily be a Rei that just loves nomming on parfaits, because someone introduced that treat to her. Meanwhile, the others could be indifferent due to not having been introduced to it, and one may even form an aversion to them, depending on the circumstances she was introduced to the treat with.
In short, it's the same dilemma we face with discerning the Personhood of AI's, when the Ego and Id are so easily replicated. As each separate entity has it's own potential for self-determination, we must treat each entity as a separate Person, regardless of the Base Product from whence they came. In the end, it wouldn't be too far an assumption to say that the scenarios presented in Doujin are at least possible, under the right circumstances, as each incarnation of Rei fresh from the Reiquarium is a new person, with her own potential and decision-making capabilities. Just like Rei III opposed Gendou, something Rei I and II never would have thought of doing, the possibility of Rei "doing something out of character" increases as new situations and scenarios are introduced for her to interact in.
Then again, porn is porn, and there is often more focus on the sexual nature of the act, instead of the personality behind it.