Quote Originally Posted by redcat View Post
I think his badge is just some device for going from human mode to shinigami mode. like that glove rukia used back in the day.
There have been too many dark, shaded panels of people staring at the badge questioningly for it to be that simple. Also, the replacement Shinigami for Karakura town had no idea what it was (or who Ichigo was, so the substitite Shinigami story was a lie they told Ichigo for some reason).