FanficRecs An unusual but worthwhile read
Basically, Shinji comes back from his month in the LCL in his mother's body. Inbetween Shinji coming out and people realizing that it's Shinji in Yui's body, Rei is told that Yui is her biological mother. Her reaction is rather extreme: sharing a futon with Shinji, becoming highly overprotective of her 'mother', and trying to set her up with at least half a dozen different women. Shinji struggles to cope with not only being a woman and a decade older than before, but also the NERV crew's different attitudes towards him/her. Meanwhile Asuka can barely intereact with shinji without her Berserk Button regarding her own mother being pressed and everyone at NERV besides Gendo (who's furious) and Fuyutsuki (who still see's Shinji as Shinji) is suffering from a combination of Even The Girls Want Her and Stupid Sexy Yui.
FanficRecs Did NOT age well
I didn't make it further than chapter 4, but here's a review anyway.
You'd think that Shinji suddenly waking up as a 30-something woman would be a great way to examine a few of the troubles trans-people have. Instead, Shinji is immediately assigned as "she" despite clear signs of dysmorphia, and Shinji is relentlessly teased for being a girl, which doesn't really make him feel better.
On top of that the author seems to be obsessed with pointing out how hot Yui Ikaris body is, and almost every character is attracted to Shinjis new body in some way. The only one that acts sympathetic is Maya Ibuki, but she has a crush on Shinji too.
A lot of people are wildly out of character, which I wouldn't complain about in a crack-fic, but this is a crack-fic about somebody forcibly having their gender changed and receiving no support at all, just pick-up-lines. Not funny, especially not post-2020.