The fog in Green Dragon Stone was getting increasingly larger and increasingly concentrated. Saleen's Elemental Eye was adversely affected, it could no longer differentiate between the things within the fog. It could only identify living targets or moving things. Be that as it may, Saleen and company appeared extremely composed.
Especially Cuisi. In the demonic plane, there were many environments like this. Many demons had already grown accustomed to hunting without any visibility, some even developed abilities which were superior to vision. Many demons had a pair of long horns. Besides acting as a fearsome weapon, these horns also possessed sensitive perception abilities.
Unlike humans, a demon's sensory organs were separated into two categories. One of which were horns and scales, these two types of organs did not contain any pain receptors and they could also regenerate. Even if the whole piece was gone, it could still grow out again.