The Promised Neverland #2-3: "The Way Out" and "A Declaration of War"
I'm honestly not sure if her being human makes her slightly less of a monster, or slightly more of one.
The Promised Neverland #1: "Grace Field House"
All their beliefs, all their security, and the only adult who they ever had - the only parent figure in their frame of reference - all gone in the blink of an eye.