Board Thread:Questions and Answers/@comment-24593407-20140227000341/@comment-8986886-20140227112424

Kamikaze839 wrote: Well, Ulquiorra did say "This is the power of a released Espada, the black Cero" when describing Cero Oscuras, so it could be implied that Oscuras is an Espada Ressureccion move, not solely Ulquiorra's.

It seems that it's Kubo's style to make a big deal of techiques like Gran Rey Cero and Cero Oscuras, only to have one Espada use them, then letting the technique collect dust in a faraway corner. (You have to give the other Espada credit for not using these OP techniques) ^^