Why do some Shinigami become Vaizard?

[Manga-Otaku]

Yeah that's kinda greedy though you know. Doing that just to get more power...

[Darkreaper70]

well maybe they felt that ss was holding them back to their true potential

[Manga-Otaku]

Funny! That's what I would feel! Like whn your a Captain SS kinda holds you back...

[Wonder jester]

the details were never throughly explained but I'm willing to bet my two cents that it has something to do with Aizen's theory of "HOLLOW-FICATION". I think Kubo wants to imply to his readers that Vizard's get there power in the vice versa that a Arrancar does.

[True]

i think it may have been done by a method of doing something to your Zampaktou spirit cause Ichigos turned into his hollow

[Useless]

not really....cuz during the fight w/ zaraki they were both there....and his hollow even said that he was more powerful than zangetsu so his body was the one u would see

[shinigami14]

I think that the vaizards were formerly apart of the 12th division when Urahara was the Captain. I believe that maybe Urahara had subjected them to the hogyoku and thats how they became vaizards or learned how to become vaizards. Thats why they've were banished from Soul Society along with Urahara. Thats why I think Shinji knows all about the Hogyoku and how long it takes to be awakened or whatever he knows about it. I also believe that Aizen used to be Urahara's lieutenant which would explain his knowledge of the Hogyoku along with his knowledge of the vaizard.