When Gu Ying had been hiding in the shadows to watch the show, he had already noticed that Ye Gu possessed the most power among the entire group. Ye Gu's power could even be beyond that of a Gold Spirit and if Ye Gu was allowed to free his hands, even with the whole group of black robed men he held in his hands, they would be hard pressed to escape with their lives.
Hence from the very beginning, Gu Ying had made everyone train all their attacks to target onto Jun Wu Xie, forcing Ye Gu to have no choice but to shield her, trapping Ye Gu's powers, rendering him unable to attack freely.