User blog comment:Xilinoc/Ch. 611 - The Soul King Dies (edgy as ever, Kubo)/@comment-25162509-20141229072147/@comment-11051098-20141229194049

Gremmy didn't need a Vollständig. He had the potential to do anything just by imagining it. IMO he was already enough OP even though he didn't use his full potential.

It would have been interesting though to see just how much stronger a Vollständig would have made him.

@LexFacie: If Gremmy had been an Elite, I think Yhwach would have held him back and let him loose later alongside the other Elites, I doubt he would have wasted Gremmy fighting someone from the Gotei 13.

He had an enormous potential with his power, but I think it's more likely, as someone theorized a while back, that he was let out with the sole purpose of taking out Kenpachi.