While the group was getting nervous about the fog, Liam's mind quickly strategized a plan. When the defensive talismans and items were not included, this fog could actually be used as a good cover for the whole group.
He waited for a couple of seconds to observe if the effects of the small damages were worsening with time. Proving his theory, the damage was actually quite consistent.
This fog was clearly set up by someone who was skilled in wind elemental magic. There were wind blades hidden in the fog that cut through once in a while. But there was also something else.
A little bit of poison in the air. A weakening or perhaps paralyzing poison. Depending on what it was it might be dangerous to let this go on unchecked for too long.