Omg yes!!! I wrote this to another reply. And I think it would tie in very well that she'll have to die so he can't have her in any way
"She will want to kill him but I don't think she will actually do it. She'll realize that Inseop is "nurturing" her violent tendencies, so she'll eventually kill someone, but she won't let him win that way"
I also wrote this character analysis of Inseop:
https://www.mangago.zone/home/mangatopic/20685731/
For the things that Inseop collects, it's not really about liking the things, but about having the power to claim them. It goes the same for MC. he doesn't like her romantically. it's about how she fits into his need for possession and control. So killing herself imo is the best revenge she could do. And because Inseop didn't achieve his goal of "power and control" over MC, it will make break him and will possibly go insane. Maybe he'll accept defeat and just surrender or maybe even turn his self in to the detective.
But what will happen to her brother after she's gone tho... Maybe the detective will take him in? Yooo imagine the end panel. Maybe a year or 2 after her death, Inseop will be all over the news that he's caught yada yada and then in comes the detective and the brother bringing flowers to the MC's grave. And it's either a snowy or sunny/windy day (depending on what vibe the author wants the story to end with)
But still I think as long as the brother is alive I don't think she'll entrust her brother to anyone anymore. Like what we've seen, she's very protective of his brother and wants to protect him herself
Better way of saying it is he'll OBSESS over the fact that MC slipped away from him, so much so that it'll break whatever facade/image of himself that he's building and go insane
because all inseop wants is to own her, i feel like for true revenge and a way to end this all is that she is gonna have to die.. but i love her sm like im rooting for her no matter what