Benioff & Weiss May Have Ruined Game of Thrones, but They Also Gave Us This
Putting these two together was a stroke of genius.
Much has been said about the damage Benioff and Weiss did in later seasons of GoT, but rarely do we see them praised for the dynamic they created between Tywin and Arya.
Of course, the performances of Charles Dance and Maisie Williams were integral to the success of those scenes. But it was the showrunners who put them together. In the book series, Arya was Roose Bolton's cupbearer. But Benioff and Weiss saw the potential to place her at the heart of Tywin Lannister's "court".
Though there was no reason to suspect that Tywin would know Arya's true identity, there was an undercurrent of suspense in every scene in which they appeared together. Would Arya be found out? How sure could she be that Tywin didn't know who she was? And what would he do if he did?
Tywin was manipulative enough that we could never be sure he hadn't identified his cupbearer as a Stark, but had simply decided to bide his time. Occasionally he would look at her with a mixture of admiration and suspicion. It was clear that he didn't quite believe her story of being a stonemason's daughter (why would he, she was pretending to be a boy when he found her). But he never let on how much he knew.
Likewise, Arya seemed to develop a wary respect for Tywin. They both knew they had to be careful with each other. But at the same time, theirs was a classic master-servant relationship. With his cupbearer, Tywin didn't have to project the same persona as he did with the council. She was too far down the pecking order for him to worry about appearing weak, and this gave him the freedom to speak more freely with her than he might with someone who might be considered closer to his equal.
The apparent class difference between the two became irrelevant when no one else was around. Instead, they became just two clever operators, each with their own agenda, a healthy suspicion of the other and an appreciation of the fact that this was a relationship built on a lie.
These scenes were always compelling. And a huge amount of the praise for that has to go to the writers. They recognised that these were two driven, intelligent characters who could complement each other and bounce off each other to make TV you couldn't take your eyes off.