Warning: Spoilers may be written unintentionally about this character. Please read at your own risk.
Former captain of the 5th Division, Hirako Shinji, suspected earlier on that Aizen Sosuke could not be trusted. He made Aizen one of his lieutenants in order to keep an eye on him, but since he did not socialize with Aizen very much, he became of Aizen’s experiments, a Visored.
Pretty convincing Shinji, don’t you think? Although I’ve never seen his zanpakuto (sword) before, so I don’t know how accurate that is. Good job!