Lucy turned to check on Arthur and when she made sure he was alright, she started walking toward Gutcha. Their primary goal is to save the pigolo then if possible, clear the Tomb. With Arthur thrown out, everything now depended on Lucy alone.
With each step taken toward the Pigolo and the center of the Heavenly Tomb which was very far away, the pressure pressing down on her became stronger.
Fortunately, her body has broken through the limiter just like Arthur so even without having access to her cultivation, she still had an unbreakable physique. It's actually an understatement to call her a moving mountain as a mere fist of her can shatter a whole mountain range and turn it into dust.
The 300m distance that initially separated Lucy from Gutcha was soon crossed. The pressure was indeed troubling but it's still no problem for Lucy to move even after taking more than a hundred steps.