Board Thread:General Discussion/@comment-6057702-20130730010329/@comment-5657895-20130909034749

Saris Khan wrote: I second the notion of the top 4 Espada (#1-#4) being Vasto Lorde before conversion, it would tie in nicely with that Resurrección restriction in Las Noches. We saw their pre-Arrancar forms and all looked the part.

Nevertheless, while very probable, it's just a well-grounded speculation without an outright official confirmation... Which kind of sucks.

I'm inclined to agree with this theory. It's the most plausible. I suppose the likes of Nel wouldn't be Vasto Lorde either, since it was said explicitly that the new Espada was stronger than the old.