>>3099759I did.
The initial speculation didn't originally stem from Shinji's relationship with Kaworu or the Anima-related BS at first, but from Shinji's relationship with Rei. If you try to picture their relationship in a non-romantic or non-pandering/shipping light throughout the movies, it becomes obvious that Shinji's relationship with her is TEEMING with parental/maternal overtones.
The most blatant example of this is when Shinji goes berserk to save and retrieve Rei at the end of 2.0. It basically parallels Unit 01's/Yui's attempts to protect Shinji in ep.19 of NGE, down to both Shinji and Yui going full berserk, bumping the sync ratio to ridiculous levels and fully absorbing the child-figure they were trying to protect into their cores. It also helps that Gendo manipulated Shinji's bond with Rei so that he would go berserk and trigger an impact, much like how Gendo manipulated Yui's bond with Shinji so that she could go berserk to eat Zeruel's S2 organ in the original show.
This isn't even taking the underlying nature and symbolism of Rebuild's impacts into consideration, which is the second biggest clue. It's all extremely sexual in nature, but I've already explained this stuff before, so a tl;dr rundown of it as follows, for those who don't know:
>core = womb>Rei = egg/fetus>blue angel goop that infected the Wuunder in 3.0 & Asuka/Eva 03 in 2.0 = sperm>impact = fertilization/fetus development processRei might actually be pre-FAR Shinji & Kaworu's true child because her "angel corruption process" triggers an impact, which then triggers the rest of humanity to "evolve." That's why the failures of infinity are all headless, and why there were giant human skulls littered around terminal dogma. Those were Rei heads.
Take it as you will, but I still haven't seen anyone on /cm/ or /a/ properly debunk these theories after so many years.
Post 2.0 Asuka is a bastard child of sorts, but that's another matter entirely.