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 Unit-01 contains the soul of Shinji's mother Yui, and Eva Unit-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 Unit-03, it's a strong possibility that Toji's mother's soul was inside of it. However, "Rei Ayanami" is a clone of Yui Ikari: Rei does not have a mother. Thus, the identity of the soul contained inside of Evangelion Unit-00 is a bit of a conundrum, and 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 Unit 00 appear several times during the series, particularly in Episode 05, Episode 14, and also Episode 13, Episode 23, and Episode 26.

The Evidence

To begin with, a large piece of evidence is that Eva Unit 00 is just a Prototype and often loses control or acts "buggy", implying that there is something different about it. As stated above, Rei has no mother, so unlike Shinji and Asuka, her mother's soul cannot be the one in her Eva. That seems to be the most obvious explanation as to why Rei's Eva Unit does not always function properly.

Some have also theorized that Eva Unit 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.

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 Unit 00. Nonetheless 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.

Episode 05

• During a startup test, Eva Unit 00 goes out of control.
  • While berserk, Eva 00 repeatedly punches a glass window which Gendo Ikari is standing directly behind.
  • Eva 00 seems to 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 Unit 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: (to herself) "No...that can't be it..."

Episode 13

Also of note is that when Rei's simulation Eva body was infected by the Angel Ireul in Episode 13, it tried to attack a control box which Ritsuko and Misato were in, but not Gendo. Misato was not present when Eva 00 went berserk in Episode 05, so she would seem to be just a bystander. However, every time Eva 00 has lost control it tries to attack Ritsuko (among others). Still, this may not be particularly significant to finding out whose soul is in Eva 00, because this was an attack instigated by the infection of an Angel, not by Eva 00 itself. Further, Ritsuko was already one of the people Eva 00's attacks were directed against in Episode 05 and Episode 14, so the incident in Episode 13 doesn't really add any "new" insights or information, but it might have led Ritsuko to the conclusion that the berserk Eva was indeed after her.

Episode 14

A "mutual compatibility experiment" is conducted to see if Shinji Ikari can synchronize with Eva Unit 00, and it goes berserk again.

• Right after Shinji synchronizes with Eva-00, he sees a vision of a rapid burst of images of Rei, saying: "What is this?! Something's trying to get directly into my brain. Ayanami? Rei Ayanami? This impression is Rei Ayanami, isn't it? Ayanami?...or maybe not?"
• Eva Unit 00 goes berserk, and repeatedly punches a glass window which Rei Ayanami 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.
  • It's possible that Eva 00 mistook Ritsuko for her similar-looking mother Naoko.

Episode 23

The Angel Armisael begins to merge with Eva Unit 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 25

• While Rei is going through Instrumentality, she sees a vision of the same wide-eyed "Rei" that Shinji saw in Episode 14 when he was in Eva Unit 00. The Episode 25 script actually specifically identifies this Rei as Rei 1.
  • 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 does not seem to be particularly changed by anything in The End of Evangelion.

Analysis

Eva Unit 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 some vital hint which she considers before dismissing as impossible (obviously implying that that is actually probably the cause). As Nerv's head scientist, Ritsuko herself actually knows whose soul is in Eva Unit 00, as she went on to state to Misato that all Evas have a soul inside of them, and Ritsuko knows that Rei is really part 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 Unit 00, but ends by saying "...or maybe not", hinting that the "impression" he sees isn't really the "Rei" he knows.

Finally, that Ritsuko pauses to consider some higher significance (before dismissing it from her mind as impossible) to Eva 00's targeting of the control box specifically containing Gendo and Ritsuko in when it goes berserk Episode 05, seems to heavily imply that the soul in Eva Unit 00 is that of someone significant; i.e. if Eva 00 has to have a soul (because of Ritsuko's comments in Episode 23), they didn't just "grab a random person off the street", as it were, to use their soul in Eva 00. The soul in Eva Unit 00 seems to have some significance.

Naoko Akagi?

A theory which circulated around the internet for some time, soon after the series aired, was that the soul in Eva Unit 00 is actually that of Gehirn's chief scientist, Ritsuko's mother, Dr. Naoko Akagi. The basis for this theory was that the three people Eva 00 attacks -- Gendo, Ritsuko, and Rei Ayanami (Rei II) -- are all personal enemies of Naoko Akagi. Gendo fooled Naoko into thinking he loved her, but was really only using her (as revealed in Episode 21). When Rei I told Naoko this, in a fit of rage and harsh realization, Naoko strangled Rei I to death. Naoko might have seen Rei as "competition" for Gendo's affections, because Gendo really still loved Yui, and Naoko was starting to make the connection that there was a link between Rei and Yui. At the same time, Naoko would want to lash out at Gendo himself, even more than Rei, because he had used her. Ritsuko actually got along fairly well with her mother professionally, and at times they seemed to be on good speaking terms in the flashbacks from Episode 21, but throughout the series (specifically Episode 13) Ritsuko says that she got along with her mother professionally but they really had a tumultuous personal relationship. Now, Ritsuko has been carrying on an illicit relationship with Gendo just as her mother used to, and Naoko might see 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 Unit 00 directly tried to attack are people who Naoko Akagi would be trying to attack if her soul were in an Eva.

Counter-argument

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 doesn't really answer the basic question of why, out of all people, Gendo (and possibly Ritsuko) would use the soul of Naoko Akagi in Eva Unit 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. If this were the case, it would explain why Eva 00 seems to try to actually kill Rei 2 in Episode 14, etc., but still it would be a bizarre choice for Gendo to decide to use Naoko's soul.
• It doesn't really address the vision of Rei that Shinji had in Eva Unit-00.
• Naoko was already dead if they wanted to use her soul: after strangling Rei I she committed suicide by throwing herself off the upper level of the command center, landing on one of her own Magi supercomputers (however, this point does not stand up at all under scrutiny; see below.)
  • 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 actually 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 Unit-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 Unit 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 II" 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 Unit 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 Unit 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.

Thus, the theory runs that after Rei 1 died, a portion of her soul was placed inside of Eva Unit 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. We do not see enough of Rei 1's personality to accurately gauge this, though (in the literally one scene in which Rei 1 actually talked, she wasn't running around laughing, etc.)

This would explain why Shinji sees a "vision" of "Rei" in Eva Unit 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 II, because they are separated: "Rei 1" (operating on a fraction of a soul in Eva 00) might be resentful that she was killed.

This would actually also fit nicely with the list of people that Eva Unit 00 attacked: Rei 1 would want to hurt Gendo because he used her, and Ritsuko as well, because she is upset that she is dead and that her soul has been trapped inside of an Eva Unit by Gendo and Ritsuko. Also, killing Ritsuko might indirectly be seen as taking "revenge" on Naoko by killing her daughter. Rei 1 might hate Rei 2, because Rei 2 replaced her and gets to be alive while she is effectively dead. In Episode 14, Misato thought that Eva 00 was trying to kill Rei while Ritsuko thought it was trying to kill herself. Ritsuko actually knows whose soul is in Eva 00, Misato does not. Still, both Ritsuko and Rei II would be potential targets of Eva 00 of the soul inside was Rei 1.

A result of this theory is that after Eva Unit 00 self-destructed, along with killing Rei 2, when Rei 3 was created she possessed her entire, reunited soul: this accounts for the difference in behavior between Rei 2 and Rei 3.

Rei 2's comment in Episode 23 that "is this the me inside the Eva?" seems to also support the theory that another "Rei", Rei 1, was the soul inside of Eva 00, and also to imply that Rei 2 was aware of this. The line, though, does seem to be somewhat open to interpretation (Rei has been known to talk in the third person like that, as in Episode 14, though arguably Rei 2 might have been referring to Rei 1 inside of Eva 00 in that episode).

Also, it must be remembered that "Rei's soul", is really "the soul of Lilith", which is being contained in the vessel of Rei's physical body (a clone of Yui Ikari's body). The idea of the "mutual compatibility experiment" in episode 14 also backs up this idea. Why would they even begin to test if Shinji was compatible with Unit-00 and Rei was compatible with Unit-01? This only makes sense if part of Rei/Lilith's soul is in Unit-00. Otherwise, there would be no reason to think Shinji could synch with Unit-00. This is another example of the Rei/Yui/Lilith motif in action, where Rei representing Yui and Lilith could synch with Unit-01 that contains Yui's soul, as well as Unit-00 which contains Lilith's soul. Shinji can synch with Unit-01 obviously because of Yui's soul, but it makes no sense that he could synch with Unit-00 were it not for the presence of Lilith's soul.

Counter-argument

The "Unit 00's soul is Rei 1" theory is actually fairly strong, with few weak spots. However there are a few points that the Naoko-camp brings up:

• Rei 1 was just as dead as Naoko was, so "Naoko is dead" doesn't serve as an effective counter-argument to the Naoko-theory, because it also applies to Rei 1.
  • Thus, if either Naoko Akagi or Rei 1's soul was used in Eva 00, Gendo would have had to get a soul from someone who was already dead. However, the science which the transfer and manipulation of souls in the series is based on, the nebulously defined "Metaphysical Biology", can be seen to effectively serve as a "magic wand" explanation in this regard: they have developed a branch of science which can actually manipulate souls, even from bodies which have died. There are several instances throughout the series where souls seem to have been salvaged from remains: Rei's soul was transfered from Rei 1 to Rei 2 only after Naoko strangled her to death, and Rei 2's soul was transfered to Rei 3 only after Rei 2 died fighting Armisael. Also, Kaworu's soul was salvaged into the Adam embryo after his death at the hands of Shinji and Unit-01. Also, in The End of Evangelion Rei/Lilith is explicitly shown collecting souls from dead Nerv personnel. Thus, "Rei 1/Naoko was already dead" is not an effective counterpoint to either theory.
• 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. However, the point seems to not be simply that someone is a mother, but that they are the mother of the actual pilot, so this really isn't a strong counterpoint. (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").
• 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. However, this seems to be incorrect:
  • Further examination reveals that the script for Episode 25, in the scene where this Rei reappears, actually specifically identifies this vision to be of Rei 1. The scene is not presented in the context of The soul in Eva-00, i.e. Rei 3 isn't seeing Rei 1 because she herself is sitting in Eva Unit 00 like Shinji was, and indeed, Eva 00 has been destroyed by this point in the series. However, it does effectively refute the idea that Shinji was seeing an impression of Rei 2 in episode 14.

Of course, a dreaded but non-ignorable possibility is that the writers might have changed their minds about the identity of the soul in Eva 00 between Episode 05 and subsequent episodes. The writing team on Evangelion is known to have greatly changed several of their original ideas for the show between when its beginning and the later episodes of the series which shifted to a drastically dark tone. Hints established in an early episode like Episode 05, i.e. Eva 00 attacking a window Gendo is standing behind, and Ritsuko hinting at the identity of Eva 00's soul, might have been meant to hint that someone else was originally meant to be the soul in Eva 00, but that this was later switched to be someone else, which hints from later episodes point to.

Conclusion

The exact identity of the soul in Evangelion Unit-00 remains without an utterly definitive answer; nonetheless it was probably Rei 1's soul, which was itself a fragment of Rei's soul (being actually the soul of Lilith).

Eva 00 had a soul, and based on Ritsuko's reaction in Episode 05, it was probably someone of significance in the storyline as opposed to just a random person's.

The theory that it was Naoko Akagi's soul does not really hold up well under scrutiny; yes, those targeted by the berserk Unit 00 were enemies of Naoko Akagi, but they were also enemies of Rei 1.

Ultimately, the series left it vague enough that if in a future incarnation of Evangelion, series creator Hideaki Anno himself reveals the soul of Eva Unit 00 was actually meant to be the soul of Naoko Akagi, yes, it would be one step above "just making it up out of thin air", and two steps above "midichlorians".

Nonetheless, just because Naoko Akagi happens to fit some of the evidence doesn't mean she was meant to be the soul of Eva 00: indeed, at no point in the series is it actually implied that Naoko was the soul in Eva 00. It is in all probability just a coincidence that people Naoko would want to take revenge on, happen to also be people that Rei I would want to take revenge on.