Board Thread:General Discussion/@comment-28503619-20160520045652/@comment-27565137-20160522150523

Kaido King of the Beasts wrote: None of the Espada were canonically confirmed as Vasto Lorde. Halibel was shown as one in anime filler but that is it. Since we have never seen a canonical Vasto Lorde it is impossible to recognize any Espada as one if they were shown as Hollows in flashbacks. Actually we can.

Toushirou said that Vasto Lordes are human in size and humanoid in form. They are extremely rare when compared to the other classes of hollows. And that supoosedly they possessed powers that surpassed even that of shinigami captains. (This last part we've seen to not actually be true)

In that regard, Starrk, Barragan, Harribel and Ulquiorra are the only one's matching the description. Yammy and Nnoitra we have no idea what they looked like before becoming Arrancar but seeing the powers and skills compared to those of the four I mentioned, they were way down the evolution ladder. Grimmjow we know he was a Adjucha, and we can simply assume that number 7 to 8 were also Adjuchas. Number 9 being the only Gillian. Because he said so himself, that he was the only Gillian amongst the Espadas. If he hadn't said that, we could even be excused to suspect Yammy was also a Gillian. Because of his size during his resurrección two forms.