Cero

Cero is a powerful and swift spirit energy-based attack used by upper-level Hollows, Arrancar, and Vizard

Description
Cero (虚閃 (セロ), sero; Spanish for "Zero", Japanese for "Hollow Flash", 'Doom Blast' in the Viz translation, "Empty Disaster" if the kanji is literally translated) is a form of attack used by Menos, Arrancar, and Vizard. Basically an energy blast, it consists of firing a blast of concentrated spirit energy at the target. While in most cases it is fired from the mouth, some Arrancar and Vizard are capable of firing Cero from their hands, fingers and other parts of their bodies. This often requires the user to under take a specific pose, with a few arrancar being the only exception.

The power, force, speed, and blast area of the Cero is dependent on the strength of the user (i.e., the stronger the user, the stronger the attack), and there are some Arrancar and Vizard who have come up with their own variation.

Gran Rey Cero
Gran Rey Cero (王虚の閃光 (グラン・レイ・セロ), guran rei sero; Spanish for "Grand King Zero", Japanese for "Royal Hollow Flash") is a Cero that only Espada are allowed to use. It is performed by mixing an Arrancar's own blood with the Cero. The result is a Cero with a much greater attack power and speed as well as a change of color unique to the Espada. It is also many times more powerful than a normal Cero, capable of disturbing the fabric of space, it also seems to spin like a razor upon release as compress and decompress due to the sheer speed and raw power. It is a drastically potent Cero, used only by the Espada themselves. Gran Rey Cero is one of two things that are forbidden while in Las Noches, as it is so overwhelming that it could destroy the fortress.

Others
While most Cero are red or crimson, some Arrancar appear to have great color variations in their Cero.Shuei Setsuna fires an purple-colored Cero with a white outline. Rebecca Seitz fires a purple and crimson cero from either one of her hands.