
:'( like for sure both personalities love him and lust over him, both of them want to exist and be with him

it's a HEA, don't worry.
take with a grain of salt bc my understanding of korean is rudimentary at best:
after this chapter the "fake" hyung gets angry then cries when jinsung tells him to switch with the "real" him and questions why it wasn't him that made him fall in love and says how terrifying and lonely it is inside his mind when he's "asleep".
and despite jinsung saying he would love every part of him, he still looks for the 'day' hyung more. this fuels the 'night' hyung's insecurities because- plot twist, he's the real-or rather the original personality and the perfect and kind hyung was the alter ego he made up because he wanted jinsung to like him and he was ashamed of who he was and how he fantasized about jinsung.
he's pleads with jinsung like, "look at me. it's the same face. so please don't hate me so much" and "what should i do? should i laugh more? i won't touch you anymore. will it be okay if i go back to the way before?" (lowkey unhinged lol bc he still had his dingdong inside him)
and there was a fundamental shift in the 'night' hyung's demeanor compared to his flippant attitude before that jinsung realizes they were essentially one and the same and hugs him. he becomes unable to distinguish between the night and day hyung anymore.
next chapter is of the night hyung's monologue and recollections. he do be fighting some demons in his head. it ends with a eureka moment of sorts where in admitting his feelings for jinsung in both the night and day versions and jinsung accepting and loving him as a whole, the night and day merges and memories flow into him.
he recalls a day where he came home messed up and covered in bruises, but young jinsung takes his hand and offers to stay with him without hesitation anyway.
so yeah, jinsung wakes up to this and starts crying from relief bc all this time he thought he was making things worse for him by keeping it a secret etc. etc. but he apologizes to Jinsung instead for all the stuff so far & says "Thank you for waiting until I can love you properly."
Later chapters+extras are hilarious and steamy because they're both jumpy af about the sex part of their relationship. They both want to do the deed but are too shy to initiate, and a couple more kinks are introduced.

this guy is either (a) a really good friend of OG jaewoo in his past life and they were v.close which is why og!uke reminded him of his friend initially. might have unrequited love for jaewoo and could be the indirect cause of his death or (b) he's the obsessed stalker/ex type and directly caused jaewoo's death and he's come to follow him even in this world
god i just wanna know blease

this definitely felt like it was supposed to be paced between a couple of chapters, but either the site cut their budget and required removal of some chapters, or the artist had to take a break and instead of announcing a hiatus and lose revenue, they rushed the ending instead
it also leaves a bad after taste because it's based around the typical negative engagement cliff hanger. ending it on that scene where one of the members overcome their anxiety or ian uncovering something wouldn't ensure reader clicks, so there's gotta be something frustrating that happens with no resolution to make sure people buy the next season even after a long break.
pretty sad when this happens to an otherwise good webtoon tbh :/
since he was protecting him from his uncles before, i think ole chairman's satisfied with his strength now (which will also be bolstered after the election) so it might be time to announce him as a contender