User blog comment:Salubri/Aizen, Yamamoto and Wonderweiss/@comment-44061-20100226142225

Im not entirely sure why there a handful of people who assume this series is nothing but a bunch of people with bankai. This is an actual story and there are plenty of shikai we dont know of. Especially in this situation where either release would be largely useless against Aizen considering his own shikai, which has been expressed multiple times. Kubo may have no intention of revealing any of this anytime soon.