High Sparrow

He arrives barefoot in King's Landing, a humble septon leading a ragged flock of the poor and devout. Soft-spoken and unassuming, he preaches simplicity and faith over privilege, washing the feet of beggars while the great houses squabble above him. Nobody in power thinks to take him seriously — a mistake, given how quickly his following grows.

Pryce plays him without a trace of villainous flourish, just patient, gentle certainty, which is precisely what makes him unsettling. The show gives him real ideological conviction rather than simple hunger for power, so his scenes with queens and kings become genuine battles of philosophy. He's frightening because he might actually believe it.