Theory and Analysis:Eva-00's Soul

Ritsuko reveals in Episode 23 that in order to function all Evangelions contain a human soul, and it is heavily implied that that soul has to be the mother of the pilot. Eva-01 contains the soul of Shinji's mother Yui, and Eva-02 contains (the maternal part of) Asuka's mother Kyoko. It is implied that all of the other potential Eva pilots in Class 2-A have dead mothers, and that Toji Suzuhara's mother is dead. Thus when Toji becomes the pilot of Eva-03, it is automatically implied that Toji's mother's soul was inside of it. However, "Rei Ayanami" was created from the Angel Lilith and the remains of Yui Ikari: Rei does not have a mother. Thus, the identity of the soul contained inside of Evangelion Unit-00 remains one of the officially unanswered mysteries of the series: to this day, series creator Hideaki Anno has given no official answer on the topic.

However, evidence and clues as to the identity of the soul in Eva-00 appear several times during the series, particularly in Episode 05, Episode 14, Episode 23 and Episode 25 and also Episode 24.

The Evidence

To begin with, Rei's Eva-00 was the first working Prototype out of a very long string of failures; it has been shown to go out of control twice and is "buggy", often returning errors when under testing. As stated above, Rei has no mother, so unlike Shinji and Asuka, her mother's soul cannot be the one in her Eva. Apart from construction defects, the soul inside Eva-00 not being Rei's mother is the next possible explanation as to why Rei's Eva does not always function properly.

Some have also theorized that Eva-00 simply has no soul inside of it at all; however, Ritsuko seemed clear in Episode 23 that an Evangelion requires a human soul to function, and she said that each Eva contains a human soul.

A counter-argument to all this, however, is that due to Rei's status as a vessel which contains the soul of Lilith she is exempt from any of the ordinary rules that dictate the process of synchronisation. This is reinforced when Kaworu, who is a vessel for the soul of Adam, synchronises with Eva-02 during episode 24 without it's core being reconfigured. Kaworu pilots Eva-02 while not even in the Entry Plug later in the same episode.

Finally, the exact nature of who or what "Rei Ayanami" is a matter for discussion in and of itself, though it overlaps with discussion of the identity of the soul in Eva-00. It can at least be said that Rei is a physical clone of Yui Ikari, which acts as a vessel for the soul of the Seed of Life Lilith.

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Episode 5

• During a startup test, Eva-00 goes berserk.
  • While berserk, Eva-00 repeatedly punches a glass window which Gendo Ikari is standing directly behind.
  • Eva-00 reject Rei, and in the process Rei gets severely injured when her Entry Plug auto-ejects.
  • When Misato Katsuragi directly asks Dr. Ritsuko Akagi why Eva-00 lost control, the following exchange takes place:

Misato: So, what caused the accident during the last experiment?
Ritsuko: We still don't know. However, we believe that mental instability on the part of the pilot was a primary cause.
Misato: Mental instability? In Rei?
Ritsuko: Yes, her mind became much more disturbed than we had anticipated.
Misato: So what happened?
Ritsuko: I don't know. But it could be...
Misato: Did something occur to you?
Ritsuko: No. That can't be it.

Episode 14

A unit interchangeability test is conducted to see if Shinji can synchronize with Eva-00 and if Rei can synchronise with Eva-01 so Nerv can implement their plan for the Dummy Plug. During this test Eva-00 goes berserk.

• As soon as Shinji is connected via the A-10 nerve to Eva-00 he sees a rapid burst of images of Rei. Shinji says:

Shinji: What is this? Something's trying to get directly into my brain. Ayanami? Rei Ayanami? This impression is Rei Ayanami, isn't it? Ayanami? Isn't it her?

• Eva-00 goes berserk, and repeatedly punches a glass window which Rei is standing directly behind. Misato even openly wonders "could it be that Unit-00 just tried to kill Rei?"
• However, after Misato finishes talking to Ritsuko, Ritsuko thinks to herself: "The person Unit-00 wanted to hit was me. I'm sure of it."
  • There's nothing to say it wasn't trying to hit both of them.

Possible Eva-00 targets.

Observe Ritsuko's hair color.

Note the details in both images. Blue shirt, open lab coat.

• It's possible that Eva-00 mistook Ritsuko for her mother Naoko. This is reinforced by these "Eva point-of-view" shots that seem to show Eva-00 seeing Ritsuko with Naoko's dark hair.
  • The production notes for the episode don't mention Ritsuko's appearance specifically. Thus, it isn't confirmed if this was an intentional hint and not a coloring error, but since the other details of Ritsuko's appearance and clothing are accurate, the change in hair color appears deliberate.

Episode 23

• The Angel Armisael begins to merge with Eva-00 and makes direct contact with Rei's mind. When Rei first feels Armisael contacting her mind, she thinks to herself: "Who's there? Me? The me inside the Eva? No, I can sense that there's someone other than me."

Episode 24

• This episode is important for our understanding of the synchronisation process between Rei and Eva-00. Kaworu is the only other example of a Seed of Life's soul present in a Lilin vehicle besides Rei who pilots an Eva. Kaworu synchronises with Eva-02 without it's core being reconfigured and later pilots Eva-02 while not present in the Entry Plug. The reason for this is that Kaworu is made of the same matter as Eva-02.

Kaworu: The Eva are made of the same body as I am. Because I am born from Adam as well. I could merge with them, if only they didn't have souls. Unit-02's soul has shut itself away for now.

• Rei is made of the same matter as Eva-01 which was grown from Lilith, but not Eva-00. However, Kaworu shows us how Rei could possibly act outside the commonly agreed rules of synchronisation.

Episode 25

• During Rei's experience of instrumentality she sees a vision of the same wide-eyed "Rei" that Shinji saw in episode 14 when he was in Eva-00. The script for episode 25 specifically identifies this Rei as Rei I.
  • A complication arising from this is the "do the original episodes 25 and 26 count as canonical, or where they rendered non-canon by The End of Evangelion?". However, the information relating directly to Rei from episode 26 doesn't appear to be challenged by anything in The End of Evangelion.

Supplemental evidence

• The Classified Information files that were included with the Neon Genesis Evangelion 2 videogame state:

"A unit called a core is used to eliminate the discrepancies in Eva, a human being with the body of a god and a soul. The soul of the pilot's mother, which is placed within the core, acts as a medium and makes piloting possible... Due to difficulties encountered in the development of Eva-00, the core's system is poorly constructed, and she falls behind in performance capacity as a result. Another reason for her inferiority is that Eva-00's pilot, Rei, does not have a mother."

Analysis

Eva-00 appears to have tried to attack Gendo Ikari, Dr. Ritsuko Akagi, and its own pilot Rei Ayanami, at various times. Also, based on Ritsuko's comment as she trailed off in Episode 05, Ritsuko knows more about the situation than she is telling Misato (of course), and there is something of importance which she considers before dismissing as impossible. As Nerv's head scientist, Ritsuko must herself know whose soul is in Eva-00, and she herself stated that all Evas have a human soul inside them. She also knows from the get-go that Rei is just one of a series of clones.

Eva-00 also seemed to violently reject Shinji, but this may not have been because of Shinji specifically, but just because someone other than her normal pilot was trying to synch with her. Shinji sees an "impression" of what he thinks is Rei while synchronized with Eva-00, but ends by saying "...or maybe not", hinting that the "impression" he sees isn't the "Rei" he knows. Rei similarly speaks of "the me inside the Eva".

Naoko Akagi?

An erroneous theory which circulated around the internet for some time, soon after the series aired, was that the soul in Eva-00 is actually that of Gehirn's chief scientist, Ritsuko's mother, Dr. Naoko Akagi. The basis for this theory was that the people standing directly behind the glass in the control room when Eva-00 punches it- Gendo and Rei, are people Naoko Akagi had a deep personal hatred for. Gendo fooled Naoko into thinking he loved her, but was really only using her (as revealed in by Rei I in Episode 21). In a fit of rage, Naoko strangled Rei I to death, seeing her as Yui (whom she very strongly resembled) and as "competition" for Gendo's affections. Naoko had good reason to lash out at Gendo himself, even more than Rei, because he had used her.

Ritsuko, who knew she was the target of Eva-00's attacks, actually got along well with her mother professionally, and they seemed to be on good speaking terms in the flashbacks from Episode 21, but more than once in the series (specifically Episode 13) Ritsuko reveals that they had a tumultuous personal relationship. Ritsuko had been carrying on an illicit relationship with Gendo just as her mother used to, and Naoko might have seen this as "competition". Indeed, during The End of Evangelion, the Magi supercomputer Casper, based on the personality-aspect of Naoko as a woman, sided with Gendo over Ritsuko. Thus, all three people that Eva-00 directly tried to attack are people who Naoko Akagi would be trying to attack if her soul were in an Eva.

Debunking "Naoko in Eva-00"

The "Unit 00's soul is Naoko" theory was popularized by several fansites for a while, but as time went on it generally fell out of favor with discerning fans for several reasons:

• It does not answer the basic question of why Gendo (and possibly Ritsuko) would use the soul of Naoko Akagi in Eva-00. As she views Rei as a rival, and even went so far as to kill Rei's first incarnation, Naoko would seem to be the worst choice for a compatible soul. Although it would explain why Eva-00 seems to try to actually kill Rei 2 in Episode 14, it gives no explanation at all why Rei was even able to synchronize with her and would remain an exceptionally dangerous choice.
• It gives no explanation for the visions of Rei that Shinji had in Eva-00.
  • The series implies that Naoko kills herself but does not actually show it on-screen. Some have suggested that Gendo actually had Naoko killed off-screen, but there is nothing to support this. Further, in the manga adaptation of the series Naoko is explicitly shown to have killed herself, though the manga is not set in the same continuity as the series; still, all points seem to agree that Naoko indeed killed herself as was implied.

Rei 1

The theory which has become more established is that the soul of Eva-00 is the soul of "Rei 1". That is, there have been three clones of "Rei Ayanami": Rei 1 (the first one, killed by Naoko Akagi), Rei 2 (who Shinji met in the first episode and dies self-destructing Eva-00 in Episode 23), and Rei 3 (who appears from the second half of Episode 23 through the remainder of the series and The End of Evangelion).

The obvious hurdle this runs into is that "Rei 2" is still alive and well, interacting with Shinji and Asuka in Tokyo-3, and surely she must be "using" her soul. However, an explanation is offered with the case of Asuka's mother, Kyoko Zeppelin Soryu. The soul of Shinji's mother Yui Ikari was completely absorbed into Eva-01.

With Kyoko, on the other hand, only a fraction of her soul was absorbed in the "contact experiment" with Eva-02. The portion of Kyoko's soul containing her maternal aspects was absorbed by Eva-02, thus Kyoko was still alive and conscious...albeit, the process of having the portion of her soul containing the aspects of her personality as a mother removed drove her clinically insane. Still, Kyoko established that part of someone's soul can be absorbed by an Eva and they can still survive.

Rei's soul, being that of Lilith herself, presents a more complex issue. Rei could conceivably have a part of her soul detached from the rest and still retain her sanity.

Presumably, an indeterminate period of time after Rei 1 died, a portion of her soul was placed inside of Eva-00, with the rest being reembodied in the next Rei Ayanami clone, "Rei 2". Coincidentally, this might explain why Rei 2's behavior seems detached and withdrawn from the world: just as Kyoko went clinically insane after having part of her soul separated from her body, having a portion of Rei's soul separated to put in Eva-00 might have drastically affected her personality, although it did not affect her to the extent of driving her insane.

This would explain why Shinji sees a "vision" of "Rei" in Eva-00; because the soul inside is Rei's, or at least a portion of it. But the segment of Rei's original soul (from Rei 1) has branched off a bit from that remaining in Rei 2, because they are separated: "Rei 1" (operating on a fraction of a soul in Eva-00) might be resentful that she was killed.

Rei 1 has motives to strike out at the same people Eva-00 attacked- she would want to hurt Gendo because he used her, and Ritsuko as well, because she is upset that she was killed and her soul has been trapped inside of an Evangelion by Gendo and Ritsuko. Killing Ritsuko might indirectly be seen as taking "revenge" on Naoko by killing her daughter (Seeing Ritsuko as Naoko implies that Ritsuko is a substitute for Naoko, from her point of view). In Episode 14, Misato thought that Eva-00 was trying to kill Rei while Ritsuko thought it was trying to kill her- Ritsuko knowing whose soul was inside the Eva.

In Episode 23, Rei 2 directly confirms Rei 1's presence inside the Eva with the question, "Is this me ? The me inside the Eva?". After Eva-00 self-destructed and Rei 3 was created, she would have possessed her entire, reunited soul: this accounts for the difference in behavior between Rei 2 and Rei 3, although Rei 3's personality appears much closer to Rei 2's than whatever is known of Rei 1's.

Finally, the idea of the "mutual compatibility experiment" in Episode 14 confirms this idea. The intention of the experiment was to see if Shinji was compatible with Eva-00 and Rei with Eva-01, with any idea of compatibility with Eva-02 being dismissed.(Strangely, even though Shinji broke his synch records during his one mission inside Eva-02). This makes sense if part of Rei/Lilith's soul is in Eva-00, for Shinji to synch with. This is another example of the Rei/Yui/Lilith motif in action, where Rei representing Yui and Lilith could synch with Eva-01 that contains Yui's soul, as well as Eva-00 which contains a part of Lilith's soul.

Counter-arguments and counter-counter-arguments

• Point- Both Rei 1 and Naoko were dead, so neither of their souls could have been used.
• Debunking- Under the (nebulous) branch of science in the series known as "Metaphysical Biology", souls can be salvaged out of dead bodies and placed in new vessels- Rei 2's soul being transferred to Rei 3 the same day that the former died being an example.

• Point- The Naoko-argument also points out that Naoko was a mother, and Yui and Kyoko were also mothers, but Rei 1 was not a mother.
• Debunking-However, the point seems to not be simply that someone is a mother, but that they are the mother of the actual pilot. (In an interview with Sadamoto in Der Mond, Sadamoto outright says "the dead mother is inside the robot, which is operated by mental/psychical bonding with the child"). In addition, in the supplemental information, Rei's lack of a mother is cited as one of the reasons that Eva-00 is less effective.

• Point- The last point brought up against the Rei 1 theory is that the vision of Rei which Shinji sees looks like Rei 2, who is a teenager, when Rei 1 died when she was still a small child, which would imply that Shinji is seeing an "imprint" left by Rei 2 in Eva 00, and not the soul of Rei 1.
• Debunking- Further examination reveals that the script for Episode 25, in the scene where this Rei reappears, specifically identifies this vision to be of Rei 1. The scene is not presented in the context of the soul in Eva-00 but it does refute the idea that Shinji was seeing an impression of Rei 2 in episode 14.

Conclusion

In the absence of a direct statement from the creators, the exact identity of the soul in Evangelion Unit-00 remains without an utterly definitive answer. However, all the evidence points to it being Rei 1's soul, which in turn was part of the soul of Lilith herself.

The theory that it was Naoko Akagi's soul does not hold up under scrutiny; those targeted by the berserk Eva-00 were enemies of Naoko Akagi, but they were also enemies of Rei 1. Nonetheless, just because Naoko Akagi happens to fit the seeming attacks on Rei 2 and Gendo doesn't mean she was meant to be the soul of Eva-00: indeed, at no point in the series is it ever implied that Naoko was the soul in Eva-00. It just happens that the people Naoko would want to take revenge on happen to be the same people that Rei 1 would want to take revenge on.