Because the Great Hall was rather dim, and the only place light could pass through was the door they had just pushed open.
Although the door was quite tall, it was still rather small compared to the entire space of the Great Hall.
Of course, it was daytime now. Once they entered, they should have been able to make out some of the Great Hall's interior with the sharp eyesight of superhumans. Yet unexpectedly, no matter who entered the hemispherical Barrier inside the Great Hall, it was impossible to see the entire hall clearly.
They could only see a few meters around the Barrier, and that area was completely empty.
It was not as though the interior of the Great Hall was entirely invisible. It merely appeared as a blurry haze, impossible to see clearly, let alone discern what was actually inside.
Standing at the entrance of the Great Hall, Zhou Ziyun said to everyone, "Everyone who just entered the Great Hall, stand where you were when you first came in."
Apart from several Martial Artists and Ability Users who had remained behind, everyone else followed Zhou Ziyun's instructions and stood roughly where they had been upon entering the Great Hall. Zhou Ziyun himself also returned to the spot where he had stood when he entered.
After everyone had returned to their original positions, he spread out his Xiantian Domain and used it to sense the hemispherical Barrier. The result was just as he had expected: the Barrier within the Great Hall seemed to have weakened considerably.
He then had Zhou Ke and the others who had just left exit once more. After sensing it through his domain again, he had more or less confirmed his speculation.
Zhou Ke found it rather strange. His Ancestor had them stand in place