The pressure of the forceful wave sent everyone in the hall to the ground with those unable to properly ground themselves rolling a few steps back. Henry was one of those who rolled.
With his guns in his hands, he had nothing to anchor himself with.
Louis rolled too but Andor stabbed his Spear into the ground and used it as an Anchor. When the wave passed, the Mummies returned to their feet almost mechanically without any actual concept of struggle.
The Mummies all held weapons and despite their obvious limited thinking ability, they knew to use those weapons to Anchor themselves and once they were back on their feet, they were quick to start striking down at the fallen humans.
With a grunt of effort, Andor rolled away just as a sword came stabbing down at him still on the ground. He got on his feet and used his Shield to deflect an Attack before stabbing his Spear through a Mummy.
