So I've heard some varying things about Rei in 3.0. It seems we've went from "She's a soulless doll" (when did people NOT say that about Rei) to "She slowly starts to develop in the latter parts of the movie." Consequently, and to no surprise, Rei Q strikes me as similar to Rei 3 in the TV series, where we went from the developed, human character that was Rei 2 to a very cold, ignorant of the world, doll of a human who, just like her predecessor, ultimately begins to develop as she's exposed to human characters. Indeed, it seems the same happens with Rei in 3.0.
The difference in Rebuild, though, is two fold the way I see it:
1. We have a whole movie for Rei Q to develop. Now, you consider that in the TV series we had something like 5 episodes (god I can't recall the exact number) and a movie for Rei 3 to develop and this doesn't sound like a lot, but given that the whole series is a movie, and it looks like 4.0 might be more character focused than it's predecessors, and one whole movie could amount to a lot of change, especially since we're left with Rei alone in a wasteland with Shinji and Asuka for god knows how long (if very long at all).
2. More importantly than #1 is that Rei 2 is still a variable in the equation. Whereas in the TV series Rei 2 died and was removed from the table, in Rebuild it's entirely possible she's still alive, if not likely. I've read that Rei 2 in Rebuild is stuck in Eva 01 but I don't know if that's official or a fan theory. Regardless, it's a safe bet that she may play a part in 4.0, which raises a whole bunch of questions to how she'd react to Rei Q and Shinji's relationship, whatever it may be, with her.
Obviously there's a whole load of questions in regards to 4.0 that the answers to which will each alter Rei's course in the movie, but I think it'd be insane to say, given the differences in both Rei's case and the plot, that Rei Q will ultimately take the same route as Rei 3 in the TV series.
Another thing I found interesting was that they seem to be really throwing around the phrase "The Ayanami Series" (or terms like it). One could say this is just casual usage of the term and I'm overthinking it but a line like Asuka's that Reichu mentions
(emphasis my own)
seems to hint at something more, almost like there's quite a lot of Rei's, and not just in the "Rei Tank" sense like we see Ritsuko destroy in the TV series. It reminds, possibly intentionally, of how you'd refer to a piece of technology by it's model type, the "The C 152 series" or something. We can also look back to the 3.0 preview at the end of 2.0 where we see 14 year old Rei and a handfull of little Rei's peaking out from behind her.
The obvious question, I suppose, is if there's more than a few Rei over the 28 year Eva history...why? In the TV series we go from Rei 1, who dies due to unexpected events, Rei 2, who dies due to unexpected events, to Rei 3, who lives until the end (or until she merges with Lilith depending on how you look at it). [s]Now, maybe we're kept in the dark and there were dozens more Rei's between Rei 1 and Rei 2 but that's entirely speculation and has little to nothing supporting it.[/s] (Previous statement unlikely considering numbering of Rei's in Reiquarium as pointed out by svenge.) So if there are more Rei's in Rebuild, why?
Is Gendo using them for experiments? This would definitely seem to go against his character in the TV series, where one of the few times he displays shock/fear is when Rei is in extreme danger, something he notably doesn't do in rebuild, but his character in Rebuild is already demonstrated to be slightly different (how different isn't quite obvious yet). So is he experimenting with or on them? Is he trying to "improve" them somehow, like you would improve a robot?
Alternatively, maybe the Rei's aren't compatible with his plans every time? Maybe they develop too fast or too slow, maybe the clone is a failure of some sort and he/Nerv puts it down? A horrid thought to say the least but Gendo never was squeamish about doing what "needs to be done."
Anyway, this is all just speculation. Like I said, it's entirely possible, if not likely, I'm over thinking things but I thought if I was going to make a thread about Rei I might as well give it a kickstart rather than just go "Rei thread? Rei thread." So feel free to utterly dismantle my theories, tell me my sources or interpretations are wrong, and call me an idiot. Or don't, I don't care, I just thought we could use a Rei thread for Rei posts.
PS: I'm not sure how the numbering of Rei works in Rebuild, so I've referred to the Rei from 1.0 and 2.0 as "Rei 2" since she fills the role of Rei 2 in the TV series.