Access Hollywood: Tom Wlaschiha Talks Jaqen, Arya, Waif

Faye Marsay is the casting surprise this season.
Seems they were looking for a particular actress to play The Waif but had to cast someone.
Like to know the story there.

Press calls her an apprentice , but , on the show, so far that only seems due to her dress.

I am disappointed that both Tom and Marsay don't have the 'black and white' robes they have in the books.
I suppose those could be 'day' cloaks and only see the official vestments on special occasions?

The Waif played a teacher in the books ,and that's been kind of hinted at, but not clear right now.
Seeing how much things have to be condensed from the books it's a little amazing Marsay has had as many lines as she had.
But then in the books Arya spends most of her time with inner thoughts and really are only two people to talk to.