it actually has been explained looooong time ago. the vizards
were originally shinigami who craved for more power so much that
they went down the forbidden path.
does this mean the current kenpachi we have achieved his captain
rank about the same time as well ?
yeah and they became outcasts from soul society which explains
their hatred for shinigamis..
i guess zaraki was also there around this time..
they're finally exploring the past of the interesting
characters..
actually which makes me wonder, if shinigamis were so strong
then compared to hollows who didnt have vastro lordes at that time,
why didn't they attack las noches.