A Misunderstanding

As they continued their journey northward on their flying swords, their speed reaching an astonishing 80 miles per hour, the group started to feel the creeping onset of fatigue. The constant utilization of their spiritual energy was taking its toll.

"How am I already so tired? We've only been flying for a couple of hours." Lily, feeling drained, voiced her weariness. 

"You're right, Lily. Our spiritual energy is depleting much faster than expected." Anna nodded in agreement, a mixture of surprise and frustration etched on her face. 

 "I'm feeling it too. Our Qi is diminishing rapidly." Emma said, her voice tinged with exhaustion.

"Flying on a sword consumes a significant amount of spiritual energy. Given our current cultivation levels, our reserves can only last for about three hours." Grace analyzed the situation, her expression thoughtful.