well i think the captains would fight if it meant losing half the town or all of it. going all out to save some of it is better than standing by and just watching it get used to make a key :P
And I'm gonna take a wild guess that his bankai does something taboo in soul society, like maybe kouryaku is a vaizard and when he uses his bankai he can't controll it, like ichigo couldn't.
And it seems ukitake has a pretty good power, i'm curious if the bankai will elevate it to that status that stark was afraid of, after all even with yama-jii fighting them seriously with his incinerating sword, they ended up with no scratches after the fight and without using bankai.
And wonderweiss! a hollow with menos grand toenails?
Although a bit short, this was a good chapter =D lots of things happened, with enough action, very un-kubo like (last few months recently anyways)
"Knowing is not enough, we must apply.
Willing is not enough, we must do."
- Bruce lee