I've been having a hard time figuring out what point that could be for Grimmjow. I do have one idea that should work, but my concern is that it is so far back in his backstory that it would physically augment what he looks like now. (I figure that he would remain the cat-like adjunchas class Hollow instead of becoming the Arrancar that he is now.) Would that be alright for the duration of the malfunction?