I stopped reading Bleach almost a year ago because of how bad it was getting and how long the current arc was being dragged out with meaningless battles. I was bored while snowed in last week, so I decided to go ahead and get caught up on whats been happening. A couple of the chapters weren't too bad, but overall its still pretty meh.

Quote Originally Posted by darkshadow
I think you are focussing to much on "activating his shikai", I personally don't believe this is needed anymore after initial exposure. Like Aizen said, "when did you start thinking I wasn't using it".

He pretty much could have it active all the time.
This is how I understood it. Once someone has been exposed to Aizen's shikai, they are pretty much under its effects permanently thereafter.

Right here it is explained: http://www.onemanga.com/Bleach/381/15/

Everyone except Ichigo has seen its release, so they are all forever under its effects.