Kimat was summoned and lightning rained down on the enemies. The powerful lightning storm not only landed on the enemies but also destroyed the wide illusion magic protecting the area. The wide illusion magic made sure that the obvious signs of battle were hidden like smoke and the loud noise.
Adrian could see the souls of the beings that are in battle which is why he did not fall for the wide illusion magic, but a normal being would have walked inside the area nonchalantly. The magic used to hide such activity is not something that ordinary illusions can pull off. Ordinary illusion magic would not have hidden the sound as it can only hide visual functions and not auditory ones.
