The High Sparrow continues to show that he and his religious band of brothers are the ones who now hold the power in Kings Landing. Following the arrest of Margaery Tyrell last week, he goes up against Lady Olenna this week and comes away victorious. As he tells her, she cannot find any possible hidden motive for him, and that he is driven only by serving the Gods. Which must make him a much more frightening proposition than any of the other players, who all have something they want, and thus something to be used against them. His sole loyalty to the Faith is further evidenced this week with the arrest of Cersei Lannister. Any understanding or partnership she thought existed between them was false, as he throws her in the cells as readily as Margaery, Loras or anyone else who commits acts that break the laws of the Gods. Hes a man with unwavering faith and no concern of nobility or wealth, and that makes him a dangerous prospect for Cersei as she struggles to fight her way out of this mess.