the perfect insider - 4
I'm not all that interested in who killed who. What's interesting are the dots being connected between Moe and Shiki/Magata/Etc, whether it's the odd dream sequence, the parallels drawn somewhat obliquely by sensei or explicitly by Magata in the flashbacks, the obsession with father figures, etc.
My undoubtedly prescient guess is that Moe is a robot and a robot that looked just like her is going to kill everyone, and in confronting the robot Moe will see that she had just chased down a mirror. We'll see her eyes open wide in shock and suddenly it'll turn red. It'll be super thrilling.