Lowkey was hoping that seoho's soul was fragmented and scattered and theyd go on a journey...

I was hoping for the same thing. The story so far has been emphasising how much lived experience and the people around you can shape you as a person so even if he were Seoho's reincarnation he'd still be his own person. The soul alone doesn't dictate who you are so to speak. I feel like them being completely different people kind of undoes all that build-up.

I don't necessarily agree! I think this is a much more interesting and unique plot twist that really makes this story more enticing in comparison to similar stories! Minchan's main struggle in his relationship w Bihwan is rooted in him not having his own identity, he is constantly being compared to Seoho and the possibility of him being a reincarnation of him expands on that, sure. But primarily because Minchan already has a strong sense of self and he feels like hes simply a replacement. But this revelation...that a "close friend" of his has been conspiring to prepare him as a vessel for Seoho this whole time??? That adds an element of betrayal and preys on his insecurity of being undesirable and incapable of truly connecting with others.

But what you said and my hoped for outcome aren't mutually exclusive? Even if he were born with a fragment of Seoho's soul as opposed to Muyeol implanting it inside him he'd still be Minchan. Muyeol trying to collect the missing pieces of Seoho's soul to turn him into what he sees as the real Seoho wouldn't be less of a betrayal if he were a "reincarnation." I just like the idea of defying what seems to be his fate and proving his identity despite what other people want him to be. Him being born with part of Seoho's soul would add another layer of triumphing against people as well as fate to keep a secure sense of self. I just really dislike how the reincarnation trope overlooks the new experiences characters go through and the interactions they have in favour of an "essence" and thought this manhwa was subverting that along with exploring subjectivity/identity. I hope I made sense. This twist is still good though I'm not really criticising the authors' choice. Just stating an outcome that would be more impactful to me personally.

I'm just conveying my viewpoint that I really don't think this new twist doesn't really keep the author from still subverting the reincarnation trope is all. I think the fact that we were led to believe this would be a typical reincarnation story just for it not to be on its own already seems to be switching it up imo. And I think we're not losing the "soul doesn't dictate who you are" bit that you mentioned bc as far as I can tell Muyeol has already started tampering w Minchan's soul it seems bc iirc he's had some moments where he vaguely feels/remembers bits of Seoho's life (idk I'm due another reread)? But all in all I get what you mean, I think I just prefer this new direction bc I've read enough reincarnation stories imo that I've also seen enough iterations of the "subversive" versions where the reincarnated person still holds an identity seperate to the og soul.