Board Thread:Questions and Answers/@comment-5239435-20130206201307/@comment-29325824-20200421062558

Darkenedhaze wrote: Someone in the series states toshiros zanpakto is rare and comes around only once every thousand years - this would mean it could be wielded by 2. Also if it dies with its master, what about the sokioku who has no master anymore but is said to have been wielded by sajin's giant ancestors

Okay, one, I don't recall it ever stating that Hyorinmaru existed before Hitusgaya had it. That alone just breaks so much canon, afaik.

Also, I don't get why people keep saying the Sōkyoku is a Zanpakuto. It isn't. It's only stated to have the power of over a million Zanpakuto, not that it actually is one itself.