I still think, he views her as an object but the only difference is that it's a living being who has its own thoughts. Regarding why he got interested in her is probably because he see him in her, like someone who can kill people. But there is a catch. Remember their childhood when both of them killed insects? Inseop killed the bugs because they were eating the flower plant. Not that he cares about the plant but he considered it was his. Whereas MC killed the grasshopper it was because it harmed the bug (an innocent thing in her view, I guess). Now the bug is the brother and Inseop harms her brother and now she's gonna take her revenge.
I still think, he views her as an object but the only difference is that it's a living being who has its own thoughts. Regarding why he got interested in her is probably because he see him in her, like someone who can kill people. But there is a catch. Remember their childhood when both of them killed insects? Inseop killed the bugs because they were eating the flower plant. Not that he cares about the plant but he considered it was his. Whereas MC killed the grasshopper it was because it harmed the bug (an innocent thing in her view, I guess). Now the bug is the brother and Inseop harms her brother and now she's gonna take her revenge.