Uchiha Yue's brief words left even Uchiha Madara stunned for two reasons.
First, Uchiha Madara had never expected Uchiha Yue to see through his scheme despite all his careful planning. Madara had always believed he was the one plotting against Uchiha Yue, but who could have imagined that while Madara was plotting against him, Uchiha Yue had instead seen through Madara's intentions?
Knowing that his thoughts had been seen through, Uchiha Madara—who had always considered his schemes peerless—was naturally astonished. Of course, what surprised Madara even more was the implication in Uchiha Yue's words: it was as though Yue had known of his existence all along.
In order to conceal himself, Uchiha Madara had resorted to every possible means. Even when controlling Kirigakure, he had used the Mizukage Yagura as his proxy. Thus, Madara truly could not understand how Uchiha Yue had perceived him lurking behind Kirigakure. Yet how could Madara have known that Uchiha Yue did not originally belong to this world? Long ago, when revisiting the original plot, Uchiha Yue had learned of Uchiha Madara's existence and all of Madara's plans.
Therefore, Uchiha Madara's shock at this moment—and his stunned state—were inevitable.
As for the second reason Uchiha Madara had been stunned and shaken by Uchiha Yue's words, it was naturally the reason Uchiha Yue had been able to break through the barrier formed by those four Kage-level experts of Kirigakure.
Unfortunately, Uchiha Madara could never have calculated just how quickly Uchiha Yue's strength had improved.
Had he known how quickly Uchiha Yue's strength had grown, the second reason for his shock would have vanished.
That was right. The barrier cast by those four Kage-level experts of Kirigakure had indeed trapped Uchiha Yue. In fact, in Yue's view, even he lacked the power to break through the barrier