
A) Fair enough. I would have never managed to remain her friend, not that I think Yeoreong is a bad person, but being next to her would make me, the bad person. It is not like I am insecure because I am, but, if everyone treats you like someone else's lackey, it is very much undermining. Being treated like someone's shadow in a daily basis sounds insufferable.
B) I think that Dan is psycho. I cannot pin the correct term for her condition, but I feel like she accepted her fate of being a side character too conveniently. Forgetting everything about Yeoreong who made her so insecure and believing she is some sidekick of a random story... She invented all those laws.
The fact that Blondie (Luka?) was a real dude and not girl is still lingering in my mouth.
Dan-I's entire persona is built on this forced normalcy — insisting she's a background character, denying her importance, and trying to fade into the background. Obsessively. It’s a coping mechanism, but it's also pathological self-erasure. She rewrites reality to fit this delusion. She stopped fighting reality because she’s replaced it with a fantasy where she doesn’t matter — even though she obviously does. It's almost like dissociation or depersonalization.
I mean, I might be tripping... But the way she remembers vividly "feelings" from a past she never knew she experienced is quite peculiar.

It is self erasure, yes because dan i is insecure and i do think its because she deems herself as a side character but insecurities shouldn’t affect your relationships. Its important to make peace with yourself because at the end of the day, you’re hurting someone who will be there for you no matter what which is rare

Although you do make a good point and it would be a good plot, she really is inside a novel Don't you remember how Dan-i and Ju-in went to a parallel universe and saw a faceless guys in suits? Also she goes to her og universe for some time (like 2 times now I think?) and her friends forget about her, remember

This: "I might be tripping... But the way she remembers vividly "feelings" from a past she never knew she experienced is quite peculiar." Why was she in that novel in the first place? Not like there is nothing to win from debating that she is not in novel (I know the end and the spoilers), but I am pushing the analysis to her psyché.

A) Totally got why Dan-I lashed out. Yeo is way to dependent of Dan-I to the point it is suffocating. The amount of social pressure and anxiety that Yeo brings her is astonishing. I can totally get Dan-I, I was once bestie with one of the popular kid (way before she became popular). At some point, I got a burnout and ghosted her. I could not keep up; our values/priorities were no longer aligned. I balance out the good and the bad of this relationship and I felt way better without her.
A.1) Still, I think Yeo would benefit from understanding Dan-I's feelings. Yeo does not seem to have high EQ, so Dan-I has a lot to gain from articulating her feelings. While those feelings are estranged, she seems to deeply relate to them. Things are different, Dan-I is well established - THANKFULLY, she was no longer in the same classroom of Yeo. Their relationship is not doomed, it can be patched. :)
Welll... I hope he rose from the dead.