Because visibility in the Blazing Smoke Ancient Marsh was extremely poor and the field of view was very narrow, disciples from various sects had to push their pupil techniques to the absolute limit in order to make out what lay ahead.
However, the vast majority of disciples possessed ordinary pupil power, enabling them to see at most two or three miles ahead; for anything beyond that, they had to rely entirely on divine sense.
Yet the intense heat of this ancient marsh was capable of interfering even with a cultivator's divine sense, directly shrinking everyone's detection and perception range down to a radius of just one hundred miles.
Chapter 4602