Grooming. That's the word that comes to mind when I see the little sister now. While she seems like the "safe" choice, I can easily see her having a huge brother complex that's not overtly obvious. A wonderful little sister that slowly closes off all the roads while gently teaching you to care for her by your own terms since any other option would end up in failure. This is working under the assumption that she's also a twisted girl though. As for Mao, I saw this coming. There's gotta be more to it though.