User blog comment:Lia Schiffer/397: Edge of The Silence/@comment-1769234-20100329162340

I have no more theories about Isshin but I have one about Aizen in his reasons for doing all of this it possible in could be the promotion of former 12th squad captain Kirio Hikifune. Aizen was already insane though he didn't have a reason to gain power as he never could reach a place of suppreme power though by hearing of Kirio's promotion he discover the power of the royal guard which is even stronger than the Gotei13 and the Soul King rules them. He figure if he became the Soul King he would be the unchallenged voice and power of the Soul Society. so what I am trying to say is that Kirio was the key that opened the plot.