Cero Oscuras

is a variation of the Cero technique used by the Espada in their released state.

Description
The Cero Oscuras is far more powerful than an average Cero, with a vast range and massive attack power. It shattered Ichigo Kurosaki's entire Hollow mask, critically injuring him in the process, and destroyed half of the dome over Las Noches. Ulquiorra compares it to Ichigo's black Getsuga Tenshō.

Trivia

 * In the manga, Yammy Llargo charges a black Cero in his released form against Ichigo Kurosaki.