56:True Face Of Eldest Son.

As he continued to absorb the metal ball its became harder to control than the previous time.

The feedback from absorbing others also became less and less as time passes. Until it came to the point of almost to the point of neglectable. 

So, when there's only five of them at last left including Wang Wei. Hall Master stopped absorbing and sat down for a few minutes to increase his control over the metal ball.

Even after trying for a few minutes. He can't even control about ten per cent of it. So he stopped the process and decided to refine it afterwards, as it may take a few months to do it.

Then he put the metal ball into another one and absorbed everything from the disciple. He continued the process, as he came near the last two. Wang Wei was the one, who now has to bear the metal ball.