"You are welcome to do so, Lord Umber. And when I am done with the Lannisters, I will march back North, root you out of your keep, and hang you for an oathbreaker." – Robb Stark
Game of Thrones thrives at subverting fantasy tropes; it exposes medieval society’s disgusting underbelly as it would necessarily be under the physics and politics of such a world. Game of Thrones not only asks us to question the nature of heroes and villains, but also the cultural bedrock of Westeros: oaths, vows, honor, and loyalty. Upholding that virtue makes a man righteous, a hero in Westerosi lore, even if that virtue comes at grave cost.