Crystal was knocked off her feet by the explosion, ending up against the wall opposite the newly formed hole. In the moment it took to regain her senses and her footing Rivka had already transformed and jumped off Selma's back to fight.
"Hey Crystal? You noticing a pattern here, or is it just me?"
Crystal gave a small smile to that, but quickly shifted her focus when Selma threw a large chunk of rubble out of the hole in the building. Which told her all she needed to know, that something was shooting at them from there. She transformed as well and took stock of the situation, walking up behind Selma to see what she saw. There was a Void there, yes, and Rivka on another building ready to shoot it. But what else? Chie seemed to be making her way back, and the officers who were with them in the room were down for the count, hopefully still alive. Crystal knew that she wouldn't be any help unless she got close, so instead she chose the other option, namely getting non-Ars Magi to safety. She picked up the nearest officer and slung them over her shoulders before shouting behind her.
"Cover me, Selma! I'm going to get these two out of here!"
She began her way down as quickly as she could before coming back up for the other officer.
"Selma, it might be more strategically viable for us to get out of here, but if you want to stay, I won't force you. I'm going to be at ground level with these two to keep them safe, so if you stay here, good luck."
Having said that, Crystal took the second officer down to the base of the tower as well. When she arrived, she carefully looked around the corner, but without the height the tower gave, she couldn't see the enemy. Still, she was on guard and ready to move if there was any movement from where she remembered the Void being.