User blog comment:Theraven22/bankai's that should be revealed/@comment-1769234-20100330191025

I believe that Urahara's Bankai may have power to control the blood of others like a puppet as its name is the red princess so it is like a princess's private army and why it couldn't help Sado train. Aizen's Bankai could create stronger illusions or that it can make them real for a short time.