Only introduced earlier in the season, but the High Sparrow has already established himself as one of the key and most powerful figures in Kings Landing. Despite protestations from the Queen, Lady Olenna and - admittedly very weakly - Cersei, he succeeds in charging Loras, and arrests Queen Margaery for good measure. Bringing out Loras' lover was a clever power move, and one that shows his reach extends pretty far in the capital of the Seven Kingdoms.