I wonder how would a Captain's reiatsu potency compare to a Vizard's or one of the stronger Espada's. I guess that if Kenpachi were to learn to communicate with his Zanpakutou he would probably be Yamamoto-Genryuusai's level in terms of sheer reiatsu, but still I guess none of them are (or have the potential to be) as powerful as the Vizards... I mean, even in Ichigo's first manifestations of his Hollow powers, he had mostly mostly shown superior powers in comparsion to a high level captain such as Byakuya. And considering that Ichigo's Vizard form and Grimmjow's Pantera are seemingly on equal grounds, it would appear that there is quite a gap between the powers of the Vizards/stronger Espada (by stronger Espada I mean from Grimmjow upwards) and the Shinigami captains. Still, I guess that's not really how things are, there must be a lot to the captains' strength that hasn't yet been shown, and also they must have been sharpening their skills like crazy since Aizen's treason.
Also, I'm very curious to see if Aizen, Tousen and Gin have become Vizards (I wonder if the hougyoku can't unlock Hollow powers as well as Shinigami). A Vizard Aizen would be seriously fucked up. Seriously.
Also, I wonder if Isshin (and perhaps Urahara and Yoruichi also?! I mean, it's not hard at all to imagine all these renegade shinigami wearing a hollow mask, if you think about it...) isn't a Vizard too. That would make the most sense, considering Ichigo's inherent reiatsu.
