"[To a young Shunsui Kyōraku] Ah, that picture... That is a monster that appeared in Soul Society long ago. It appeared when Soul Society was in great need and only brought further turmoil. It will not trouble us again. If, someday, that monster were to appear before us again... I fear that will be the last day I am ever seen in this place."
January 1, 1970
https://en.wikiquote.org/wiki/Bleach_(manga)