Oh, this is getting a little more interesting now that onii-chan is the one spiraling into the abyss.
Right, his main objection last time was because he felt that he cheated on his ex-girlfriend. Not because he committed incest with his manipulative, underage blood-related sister...
Will the guilt crush Himari again? Of course she also dug her own grave with this, but we'll see how she handles this (or fails to).