Chapter 100. Aizen didn't really die back then. He faked his death in order to make his goal easier. After his defeat by Ichigo, he was imprisoned in the Soul Society prison. In truth, Aizen can't die, because Urahara and the Central 46 said the Hogyoku has made him immortal.
Chapter 100. Aizen didn't really die back then. He faked his death in order to make his goal easier. After his defeat by Ichigo, he was imprisoned in the Soul Society prison. In truth, Aizen can't die, because Urahara and the Central 46 said the Hogyoku has made him immortal.