Board Thread:General Discussion/@comment-24744083-20140816161121/@comment-8986886-20140824135726

Aetheral wrote: Hmm, yes... And of note is the fact we do not know if the Kido corps work in similarity to the divisions of the Gotei 13 (meaning it might be valid for Hachi to have just Shikai and Tessai to have a Bankai as well. Which if so, would likely make Tessai stronger either way) But they probably have some skill with their Zanpakutō and haven't even used it yet.. Neither has Yoruichi... Not sure if they will though. Depends on what Kubo has planned

I guess it's possible that Tessai's got a Bankai, but I believe it's called Kido corps for a reason. Kido is their primary weapon and therefore each member's mastery of Kido should determine their rank within the organization. Besides, if you've mastered 80s and 90s lvl Kido spells and probably developed a few unique techniques in addition, like the ones Kisuke and Hachi have demonstrated, would you even need a Bankai? (Hachi did quite well against Barragan, relying on Kido alone)

Members of the Gotei 13 rely mostly on their Zanpakuto in battle, so it's only natural that mastery of Zanpakuto techniques, as well as achieving Shikai and Bankai, have a great impact on division members' rank.