Board Thread:General Discussion/@comment-6746577-20131127231527/@comment-1387259-20131127232346

Well you have to remember that he was lying about what his Shikai could do for years upon years, since his Zanpakuto was completely based on crating illusions. So chances are he was lying about what his Bankai could do, and used his Shikai to make the lie reality. With that, he could easily pass the exam without having to reveal anything he couldn't risk revealing. It's also possible (though this is really just a theory on my part, take it with a grain of salt), that he actually never achieved Bankai, but once again, used Kyoka Suigetsu's abilities to fake having one.