As for Cheng Ming, he had already arrived at the center of the formation before them. He had carved up a path for Gu Xiaoyue and the others. The core of the formation was an ordinary looking gravestone. It looked very old, and Cheng Ming's methods were simple -- he sent a punch right at it.
With that punch, Cheng Ming's fist was immediately split open. The gravestone only had a mild crack on it. However, he was elated, as the extreme hardness of that stone meant that there was definitely something strange about that. It meant that Gu Xiaoyue's guess had been correct; that was the core of the God Sealing Array.