User blog comment:Godisme/San'ou/@comment-5332138-20120725203226

I think you're being too quick on your assumption. We don't even know if either Rukia or Renji are KO'd. They got hit once, I doubt it would be enough to knock them out of the fight.

As for Byakuya, I don't consider him dying but revealing a mechanic to a potentially ridiculously powerful ability pointless... He did what he said he would do, reveal how the enemy fights. That's an extremely good advantage to have when you're in battle. You knowing what your enemy can do through seeing it is way more useful against the enemy assuming what you can do because they read files on you.

Kubo mentioned Kenpachi was one of the three strongest captains. Right behind Unohana (2nd strongest) and Yamamoto (strongest).