Could Arya have used the Mountain's face?
Had Arya killed the zombie Mountain off could she have then used his face? Would that have been possible for her to do?
I was thinking about the idea of Arya pretending to be the Mountain to get close to Cersei, but gets killed by the Hound in the process who thinks it actually is his brother. Might not have looked very believable but could have created a great, shocking moment. I didn't feel there was enough shock value in this final season, and they missed a trick with Arya using her faces for a potential twist.