So we all know that the hogyoku was the main driving force of bleach's plot. But I've been wondering what exactly it is. I hope we can all agree that upon appearance it appears to be a form of energy contained within a case. I'm also hoping we can agree that the hogyoku refers only to the contents of the case and not the case itself. but this leads me to wonder. what is the hogyoku? is it a life form? some sort of biological being? it seems to behave as one in its ability to detect hearts. it may also be tech, considering the fact that it can be created. I however believe that it is a type of spiritual energy, scientifically generated and then captured in the case. what the hogyoku makes me think of is radiation. like a radioactive spiritual energy that contaminates and changes those closest to it. anyways, I'd like to hear what you all think of this.