The most difficult test in history

When the elder saw the number above, his face changed drastically, with a look of disbelief on his face. "How can this be?" Everyone was shocked, and even an elder-level strong man changed color. What on earth was going on? Tu Fang sighed and said, "If I remember correctly, the guy imprisoned in that cave has probably been challenged for some years." Tang Wan'er was startled and asked hurriedly, "How old is this cave?" She sensed something was wrong at the first moment. Even the elders changed...