From the very beginning, Shen Feng had never equated the Purification Society with the Whisperers.
After all, if the Purification Society truly possessed power on par with the Whisperers—where a single Hypnotist could sway the world and annihilate a civilization—then Cthulhu would have had no need to burn the Purification Society to the ground back then.
The sanatorium massacre would have been equally meaningless.
Cthulhu could have simply used Hypnosis on the powerful dignitaries who came to him for treatment. He could have had them incite a world war, or just keep hypnotizing more and more people until everyone harbored thoughts of self-destruction.
Based on Shen Feng's current understanding, if a Whisperer could manifest physically in the world, it would very likely possess such power.
But instead, Cthulhu created the much lamer Purification Society. He even orchestrated a bizarre massacre in the so-called apocalyptic year of 1999, destroying all of Wuyou Town.
