A dialogue goes on in bleach that is legendary for me
byakuya: you understand, don't you? your bankai has disappeared. the disappreance of bankai against one's will means its owner is near death. you will soon disappear. i will ask you once more. even now, will you spout foolishness about saving rukia?
renji: of course...
byakuya: what?
renji: i swore that i'd save her no matter what.
byakuya: you swore to who?
renji: no one. just to my soul!!