The Radiant Wave Shield has similar technology to Wallace's Lotus Mech Frame. The shield it creates wouldn't just protect them from external attacks but it was also capable of counterattacking.
"This should be good enough. We need to have a good rest..."
Wallace said after setting up the machine at the entrance. They've just survived a disaster and the reason they were attacked was most likely due to his actions.
He glanced at a certain direction as if he was observing something from afar.
A while ago, he decided to halt their advance not just because it was about to get dark but he realized that the chimeras hiding in the shadows seem to be very dangerous.
He saw their large and sharp claws that can cause them some serious injuries if they were not careful.
Now, he noticed that they were not moving from their previous location so they can only act that they haven't noticed their presence yet.