The thought of that makes him uneasy, something he's not quick to let on. Is there nothing the Tevinters won't touch with magic? Time, the dead, blood, even if Dorian himself stays away from that latter. "Ice would be quite useful in the fog. You're right that lightning would be to our detriment then, as well as in the dark. We don't want to alert them to us if we can help it."

Oh, eventually they would know they were being cut down and had warriors and mages in their midst. There's no sense in advertising to camps further away. He'll be advising minimal use of fire, too, for the same reasons.