Group Three Versus Group Six

The middle-aged man's sudden death stunned the other eight people in the cage. Their expressions were one of horror when they shifted their eyes back to the young man, looking as though they had seen a ghost. All of them were familiar with the middle-aged man who died. They knew the middle-aged man was stronger than them, and yet, the young man had easily killed the middle-aged man in just a blink of an eye.

Most of them were confused and shared the same thought at this moment. Why was the young man in the grade-three secret realm when he could easily enter the grade-two secret realm with his strength?