Ok, so, Asuka's Mother.
Canon Stuff We Know:
Dr. Kyoko Zeppelin Soryu was half-Japanese, half-German. She was married to Mr. [No Canon First Name] Langley, and was head scientist for Project E, NERV-03 (Berlin). In the aftermath of Yui Ikari's 'failed' Contact Experiment in late 2004, Kyoko and her team modify the Contact Experiment setup for Unit-02 with safeguards to prevent physical absorption. In early 2005, Kyoko attempts a Contact Experiment with Unit-02. Part of her mind and soul are pulled into the Core, and what's left in her body is insane, unable to even recognize Asuka as her daughter.
She is placed in a mental hospital, where after several months she hangs herself, along with the doll she'd crafted and treated as a beloved child. Asuka is the one who finds the body, as she was running to tell her Mama the good news that she'd been selected as Second Child, in the hopes that the news would get Mama to look at her again, not the stupid doll.
During this time, Mr. Langley had been sleeping with the female doctor assigned to Kyoko's case, at times literally in the room next door, where Asuka could hear it while she stared at her mother who no longer knew her. Needless to say, this was
slightly traumatizing to Asuka. Mr. Langley and the doctor are married by the time of Kyoko's funeral. Asuka swears at her mother's graveside never to cry again, to grow up fast and be an adult who needs no one, and
make people look at her.
Asuka's father and new step-mother make token efforts to get Asuka out of her withdrawn and angry state, including buying her childish toys like the stuffed monkey we see, but Asuka is not fooled, and they soon give up, basically turning her over to NERV to be raised as Unit-02's Pilot. Asuka maintains a superficially civil relationship with them (such as the phone call from her step-mother we see her take), but in reality is isolated and lonely, with no true affection or closeness to anyone since her Mama's death.
During SEELE's assault on NERV in
End of Evangelion Misato orders Asuka, catatonic since her passive suicide attempt, dressed in a plugsuit and placed in Unit-02 and launched, judging that a safer place for her than laying in a hospital bed that SEELE is about to overrun. Unit-02 is launched, and ends up laying on the bottom of the Geofront lake, Asuka curled into a fetal ball in the Entry Plug. When the JSSDF detect her, and start dropping bombs on Unit-02 at the bottom of the lake, we get this:
Asuka:
...I'm alive...
(Shots of depth charges firing and exploding around EVA-02)
Asuka:
(Whispered at first then repeated growing louder and stronger)
I don't want to die... I don't want to die... I don't want to die...
(Another voice mixes with Asuka's)
I don't want to die... (You're still alive) I don't want to die... (You mustn't die yet) I don't want to die... (You must live) I don't want to die... (I won't let you die) I don't want to die... (Don't kill me) I don't want to die... (You're still alive) I don't want to die... (I won't let you die yet) I don't want to die... (You must keep living) I don't want to die... (Die for me!) I don't want to die... (You mustn't die yet!) I don't want to die... (Die!) I don't want to die... (You're alive!)
I don't want to die... I don't want to DIE!!
(Flashback to Asuka as a child with mother)
Child-Asuka:
Mama... So this is where you've been? Mama!
(Asuka clasps her mother's hand and EVA-02 awakens.)
Ass kicking of the JSSDF and MP Evas then ensues until her battery runs out.
Speculation, Conclusions, and Fanon:
Kyoko was one of the few experts in the world at the time of her death in the new field of Metaphysical Biology, the science of souls and Evas. In such a new, small field, she at the least knew of, and probably met personally with other experts like Yui, Gendo, and Professor Fuyutsuki. She could have been Yui's friend, rival, anything, we don't know. She in all likelihood did
not know that Yui's 'death' was intentional, or that a soul could be trapped in an Eva Core through a Contact Experiment: we've seen nothing that establishes she had foreknowledge like Yui did, and Asuka and Unit-02 were entirely expendable extras irrelevant to SEELE or Gendo's plans for fighting the Angels and triggering their own Third Impact. So Kyoko was probably going in blind, and had no idea what the CE would do to her. I can't see her willingly tearing her soul in half and leaving the rest of herself to commit suicide and traumatize her daughter, anyway.
Since we hear two distinct voices in
EoE, it appears that either by SEELE's salvaging technology, or by migration once her body died, both pieces of Kyoko's soul end up in the Core, and either remain split, or leave Kyoko with a divided personality, given that after ten years in the Core, she's still not speaking with one voice. So even if a means to extract her from the Core is possible, you're still left with a soul that is either in two pieces, or crazy, or both.
As someone said above, you've still got the problem of 'it might not be possible to get someone out of a Core and leave it empty', that doing so might render the Eva dead/non-functional, and my own assumption of 'you can't make an unwilling soul leave a Core short of destroying the entire Core'.
We also have very little on what kind of woman Kyoko was before her accident. Hints are that she was a driven scientist, willing to take high risks, and tended to let her job take priority over her family. Asuka's idealization of her Mama is partly faint childhood memories overlaid with 10 years of longing for affection, so we don't really know, though Kyoko seemed very happy to finally talk to her in
EoE, and Kaworu says he was only able to puppet Unit-02 when he hijacks it because 'the soul in the Core has hidden itself away', implying Kyoko deeply withdrew once Asuka was no longer the Pilot.
Argh. I think I had more, but cannot recall what. I'll add it in later if it comes to me. For now, I hope this datadump helps clear things up.
