Almost everyone in that park had their attention on either one of the two battles. It was either the battle between Xian Yang and Yang Jun, or between the Swift Spirit Sparrow and the Pledge Demon. Thus, they didn't notice when two people previously involved in one of these battles were gone. These people were Amon and Tuang Yin.
Xian Yang was the first to notice their disappearance and put in the effort to locate them. He found Tuang Yin, surprised to find her a distance away. At first, he thought she and Amon would cooperate with Yang Jun to take him down.
Tuang Yin was not the target Xian Yang was looking for, though. He was looking for Amon. He was worried that Amon had run away. It was a rare opportunity to find Amon outside the protection of his faction and the Royal Academy. Thus, he couldn't miss this opportunity.
