I don't quite understand what Cersei is trying to do. I take it she's not as smart as she thinks she is, as Tyrion and others have made clear in the past but I can't see any way this can end well. I mean, to allow the creation of an armed force with the mandate that can challenge your power and the life of your son. Seems dim, even for her.
I guess her experience with that witch in her childhood had left a mark and now she's jealous and afraid of losing everything.
That scene with Arya in the room full of heads was impressive. I wonder if they use the faces as inspiration for their shape changing.