At that time, there were too many people gathered in the ruins of the Five Sounds Sect, and the crowd was mixed, so he didn't quite believe that claim. Even later on, when all who remained were experts, no one mentioned that Cao Zhen was from the Hundred Peaks Sect.
Thus, he was always skeptical of that statement.
Now, hearing Cao Zhen personally admit that he was from the Hundred Peaks Sect, he was completely shocked!
Cao Zhen was a limit existence at the Golden Core Period, and he had reached the limit of Golden Core Period when he was a Nine Abnormal Phenomenon Golden Pills, how could such a person not come from a Great Teaching but from a mere Sect?