#twny

methodology:

i narrowed it down to 3 instances, but virtually, it could happen at any moment, since there are no rules. since i took inspiration from tomie (let's ignore the more gruesome aspects of her power, namely the mutations, murderous intent, and cloning), reader can rearrange herself from a single strand of dna... which means she could only grow in a place that either has the most of it concentrated or has any of it left. hence, she really IS immortal. there will always be something that could bring her back. a strand of hair in some unsuspecting corner beneath the couch and poof, she's back, baby

timeline:

directly after the death report is submitted

realistically speaking, since she's a very clean individual, it's unlikely that she'd appear in her room. most of her dna would likely be concentrated in gojo's dorm, which, hello, is terrifying. your dead gf just rises up one night and you think you're dreaming but she's really here

i don't think gojo could really take that without going through the 5 stages of grief again. he'd likely be so angry he wouldn't recognize it's actually her and attack. say he doesn't accidentally end her again and somehow restrains his first "what the fuck is this curse and why is it mocking me" reaction and actually believes her. he'd probably feel so betrayed he couldn't even look at her

then, it would come down to telling the others or not, and he'd need to make a decision fast. if he tells the higher ups and the staff, there's no telling what experiments they'd decide to perform. after all, we have a character that's immortal (almost kenjaku-esque, just without the brain jumping) with cells that can clone and heal. it's likely she'd be taken to a lab somewhere, which presents us with:

a) gojo goes coocoo coconuts and kills the higher ups, hence sending the jujutsu world in disarray. this ending would likely result in him becoming an unhinged yandere. bad ending

b) he tells the staff, they send reader to the labs. he never forgives himself, even if she's fine in the end. bad ending

b.1) in the same vein, reader goes through the experiments. she might end up hating sorcerers after that. she is a kind and fair person, but i doubt she could psychologically take it. reader becomes a curse user, and would likely (much later in the jjk timeline) be on kenjaku's side. very bad ending

c) he doesn't tell the staff and goes full yandere since he needs to hide her and make sure nothing happens to her again. it's likely she would never leave the gojo estate. bad ending

if he tells the staff and no one performs any experiments, he wouldn't be able to trust her for a long time if ever, because he would view her death as leaving him, much like suguru. the rest would also be heartbroken and likely never view her the same again, not exactly because of her powers, but because of the emotional impact she left. it's unlikely that gojo and her would get back together without it quickly becoming twisted in some way, because gojo couldn't emotionally take it. bad ending

2. getou's cult era

say it took longer for the cells to grow and gather again. she'd still be 20ish and gojo and getou would be 27/28. no one would believe it's actually her. i think she'd feel very lost and alone, and getou might go a bit coocoo coconuts and try to recruit her. if he succeeds (even via kidnapping), you can expect some yandere shit to occur. if he fails and satoru saves her, the experiment question comes up again. bad ending which ever way u look

3. the culling games

here i think she'd be drafted without really knowing what's going on. when examining the player names, the staff and megumi would likely see her name, which would lead to an immense amount of discord. megumi would be so pissed bro. again, no one would believe it's actually her

i think she'd also be more likely to meet yuji first and only see megumi again as sukuna. it would feel really weird for her to see anyone from old jujutech, since she'd still be 20ish while everyone else is almost ten years older

it's unlikely anyone that knew her previously would trust her. maybe yuji would vouch for her, but the rest would have some thoughts. either way, there's no scenario in which she and gojo end up together again in this case, doesn't matter if he lives or dies. he'd treat her more as a ghost and a memory, having a lot of mixed feelings. bad ending

conclusion:

this is not even taking into account if she would return without her memories, which adds a whole other spin. either way, she could never see her family again, and she would outlive everyone. i wouldn't be surprised if she eventually ended up like kenjaku. u could draw an interesting parallel with that.