Damn that's fucked up. Chapter 10 really put the whole thing on another level. Yeah, the only part that I don't like is how guilty the MC feel about killing that guy, he should be proud.
That manga brings a good question of "why do I love?". You can argue that it's a romantic or paternal love but it's love nonetheless. Why? Why the urge to protect, why he feels responsable for her? I've been thinking like that lately, about my gf. Why?