There’s a fair amount of preening and posturing in the upper classes of Westeros, from Theon’s impatient egoism in the North to Joffrey’s bloodthirsty bitchiness in the South. But it’s been clear for awhile now that the only people who really understand what’s at stake in the titular Game of Thrones are those who don’t need to pretend to be something they’re not. The most successful players are all terribly, visibly scarred: Bronn and his oft-broken nose, Tyrion and his equally shattered heart, Varys and his missing bow and arrows. In “Blackwater” — the noisiest, wildest episode of the series to date, a bravura battle royale of action, emotional savagery, and unanesthetized trepanning — the biggest turn was reserved for the most marked man of all.