Back then, after his cultivation broke through to achieve 'Cyan Sun Golden Immortal', Wyatt Barnes discovered he could control more grey flames.
The additional grey flames, after his cultivation further broke through, then left the fragmented metal piece and merged with the part of the grey flames he could already control, becoming part of that grey flame.
This also caused that part of the grey flames to grow significantly.
And now, after his cultivation broke through again, achieving 'Blue Sun Golden Immortal', Wyatt Barnes found more grey flames leaving the fragmented metal and becoming part of the grey flames he could control.
Looking at the current situation, by the time he breaks through to achieve 'Daai Law Golden Immortal', all the grey flames inside the fragmented metal piece should be able to come out and merge into the grey flames he can control, allowing the grey flames to further grow.
