The moment they were given permission by Claire to move forth, Rong stayed on the walls while the others jumped into the burnt clearing and continued into the forest.
The reason why Rong stayed back was mainly because of his unique cultivation that allowed him to pull them back to the walls if the situation turned dire.
This extra precaution was sorely needed with the firestorm within the forest still raging on. The team of newbie Demon Exorcists might be high grade cultivators with the ability to hold their breath for an extended period of time, but should they get stuck, there was a need for an escape route.
Hence, Rong came into the picture by enabling his cultivation of the Ox Demon Ao Ye. "Advanced Ao Ye Technique, Hair Tracking Ropes!" Rong shouted.
Despite the name, the hair ropes actually emerged from his hammer and they were like an extension of the hammer because of the particular technique. (Not his hair!)