Arya got a little creepy. But I fundamentally think she's right about Sansa and we saw it for a brief moment when she was talking shit about Jon and the Battle of the Bastards.
#TeamArya
Giving Sansa the Valaryian steel dagger had some significance in my mind, as well as letting her see the faces. Arya let Sansa she what she was capable of, talked about the importance of doing everything for family, then gave her the best weapon in her arsenal. Yeah she was creepy about it, saying how it could be fun to be her, but in that scene it was very clear she *could* have killed Sansa and taken her face, but didn't. It was basically Arya telling Sansa that even for as pissed as she was, she put Sansa first and would protect the family.
The writing is getting sloppy - the fact that they have less episodes and one season left to wrap things up is causing things to be cut and deus ex machinas to pop up left and right (Benjen anyone?). But, still a fun episode and still a fun show; not gonna complain.
Benjen is like a built in deus ex machina, but I can live with it - not like he has much else to do besides tracking anyone who comes north of the wall. Plus he at least go established in S1 and S5 with Bran, so he's not a total out of the blue thing.