User blog comment:Xilinoc/Ch. 574 DEATH IN VISION/@comment-3405923-20140326153450/@comment-24739129-20140326190247

The power probably does work both ways, and Yachiru wanted Kenny to come save the day. That's why Gremmy constantly is "Suggesting" things to his opponents, rather than telling them outright what it is. Maybe the key is the opponent has to AGREE with him? Seems like the instances where his power fails him are when the user is not in agreement..Kenpachi being drowned (he believes theres nothing Gremmy can do to kill him), Kenpachi cutting Gremmy, Yachiru's bones returning to normal.

Or Kenpachi is just flat out miles ahead of Gremmy, and AGAIN dragging out a fight in an attempt to enjoy it.