Istg, some people are just brain-dead. Honestly, when they blame sejin for the first time line, i feel like they haven't read a single panel properly.
In the first timeline, Sejin's adoptive father clearly deceives him by saying that that document or whatever was the agreement of the contractual marriage which Ido still didn't handover.
To me, no matter what a person does, raping them is never a punishment or atonement. It's plain RAPE!!
These people who are saying that Sejin should stop his nonsense are no different from the people who ask, "What was she wearing?" to a victim of rape.
Seijin never experienced warmth to know what toxicity is. Back then, though Ido was kind for a brief while, it was all too new to Sejin. Besides, in the first timeline, Ido said some really arrogant and hurtful comments to Sejin( for example, the first meeting, the first outing by the Han river, the first sex...) which made him think that there's no way he'll be there for him when he(Seijin) has no family.
We see that what happened in the first timeline, what Seijin did wasn't really what he would've done. From his heart, he is a moral person. Because in the second timeframe, though everything was the same, just because Ido showed genuine kindness(though out of guilt) Seijin chose a completely different path.
No matter how much one repents, the fact that someone killed themselves because of the abuse they endured can never truly be repaid. The only cost of a life is another life.
Which the author depicted perfectly in the novel. Don't know about the manhwa.
I think BL culture really messed up people's perception of someone's suffering. We've gotten so used to seeing characters being raped, thrown around, and humiliated that it kind of desensitizes readers to it.
Manhwas in general are way too quick to blame the victim or frame the whole abuse arc as a shared responsibility - to the point where readers completely lose the plot. Nothing, and I really mean nothing, justifies rape, isolation, or violence.
As you said, Ido could already be perceived as psychologically abusive even before the whole rape incident. The guy was a condescending asshole from day one and only got slightly better once he caught feelings for Sejin.
Yes, Sejin had his flaws in the first life, but they were just consequences of his deep fear of abandonment. His adoptive father manipulated him, lied to him, and treated him like a tool his entire life. How can you expect someone like that to make rational or calm decisions when abandonment feels like the absolute worst thing that could happen to him?
And since when do you forgive rape because of
industrial spying??? Nah, i could yap about this for hours.

I don't care what people say - the man could crawl for another decade and it still wouldn't be enough.
Seeing so many people claim that the story is dragging while Sejin is literally processing the return of his memories and the trauma that comes with it is just confusing. You don't need to hate your aggressor to keep your distance from them. And Ido being sad and sorry doesn't erase what he did to Sejin in the slightest. I'm just happy to read a good "chasing" arc where the victim doesn't give a single crumb of pity to his abuser - while still not demonizing him. Yes, Ido loved him. Yes, he sincerely regrets everything and gave him a better second life - but that's the bare minimum. God, the only reason Sejin is staying away from him is because he thinks Ido will abandon him all over again.