A long time ago in a Westeros far, far away…
WELL. YouTuber Omid G. has edited the scene to include lightsabers, and it's frickin' amazing:
It starts out with Brienne and Pod doing their usual training, BUT WITH LIGHTSABERS:
HBO / Omid G. / Via youtube.com
But then Arya shows up WITH A PURPLE LIGHTSABER:
Because of course Arya would be the only other person...