Something strange happened to the red vests worn by the Holy Place's infiltration team. It was so slight, however, it didn't arouse any suspicion among the wearers.
Xia Zhou didn't want his Blood Element Servants to be too brutal or savage which could potentially incite an uproar among the highly stressed members of the infiltration team, distracting them from their mission to deal with the plane fusion.
For instance, the red vests on Serites and Rexasor began to extend slowly from the back of their necks. An almost transparent light-red "fabric" spread from the base of their necks, toward the back of their heads, and then moved slowly toward their ears.
Throughout the process, the light-red "fabric" never made contact with the wearer's skin.
The Demon Hunting Masters might have felt this contactless oddity, but they were apparently too preoccupied to notice the changes in their vests as the plane fusion began.