Espada

The  are the top-ranked Arrancar in Aizen's army of Arrancar.

Outline
The Espada are regarded as the strongest Arrancar in existence. At the time of the group's introduction it consists of nine males and one female. Each Espada member is chosen for their superior combat ability and then assigned a number from 1 to 10 that indicates their rank and relative power level, which is tattooed somewhere on their body (Grimmjow's is on his lower back, for instance).

The Espada are given free control over the Números and may choose as many of them as they like to become their Fracción. Similar to the power gap between captains and lieutenants in the Gotei 13, the strength of the Espada far surpasses that of the average Número, and Aizen himself is confident enough of his Espada's abilities to send them out on potentially hazardous missions, such as gathering information in the real world, fighting Shinigami captains inside Las Noches and Karakura Town by themselves, and gathering the Vasto Lorde. "Gran Rey Cero", which Grimmjow Jeagerjaques refer to as "the ultimate cero", is an Espada-exclusive technique. Further reflecting their status as the leaders of Aizen's army, each Espada is given a device, known as "Caja Negacion", used to punish arrancar subordinates by trapping them eternally in an alternate dimension, though it cannot be used on another Espada.

Being Aizen's most direct subordinates (not counting Gin Ichimaru and Kaname Tosen), the Espada are privy to several of Aizen's plans and most intimate secrets, such as his goals of destroying Karakura Town and creating the King's Key, the location of the Hougyokou within Las Noches, and the name and illusory abilities of his Zanpakutou. Aizen's respect for the Espada's abilities is reflected on his manner of addressing them, often referring to them as "my dear Espada" and sitting at the head of the same table with them while discussing the events around Hueco Mundo.

As Aaroniero Arruruerie notes, all of the Espada except him were at least adjuchas-class menos before becoming arrancar.

History
While it is not specified when the Espada were first created as a group, it is implied that the original Espada were already in existence sometime before Aizen's defection from Soul Society and acquisition of the Hougyokou. Since then, the composition of the Espada has changed, reflecting a change in membership and position. Before his death, Aaroniero Arruruerie was the sole member of the current Espada who was also part of the first-generation Espada.

Ranks
Stark, Barragan, and Halibel's numbers have yet to be revealed.
 * Neliel Tu Oderschvank is the former third
 * Ulquiorra Schiffer is the fourth;
 * Nnoitra Jiruga was the fifth;
 * Grimmjow Jeagerjaques is the sixth;
 * Zommari Leroux was the seventh;
 * Szayel Aporro Granz was the eighth;
 * Aaroniero Arruruerie was the ninth;
 * Yammy is the tenth;

Demotion
An Espada may be demoted from the Espada, such as Grimmjow Jeagerjaques when his left arm was cut off by Kaname Tōsen. In most cases they will be demoted to the, who are former Espada that have officially lost their rank and are assigned a three-digit number.

Current events
Currently, the Espada have lost four members (excluding Luppi, Grimmjow's temporary replacement);
 * Aaroneiro Arruruerie was killed by Rukia Kuchiki;
 * Szayel Aporro Granz was killed by Mayuri Kurotsuchi;
 * Zommari Leroux was killed by Byakuya Kuchiki;
 * Nnoitra Jiruga was killed by Kenpachi Zaraki.

Grimmjow Jaegerjaques was incapacitated by Nnoitra Jiruga, Yammy's location is unknown, and Ulquiorra was left in charge of Las Noches while Aizen, Tōsen and Ichimaru, along with Stark, Barragan and Halibel (the top three Espada) and their Fracción, battle the Gotei 13 in the fake Karakura Town.

Interesting Fact
Interestingly enough, the titles of the Espada are split into both Spanish and Italian titles. For example Espada's 1-5 are all Spanish numerals while 6-10 are Italian numerals (Sexto, Septima, Octavo, Noveno). If you notice during many of the Espada's formal introductions, like Ulquiorra & Nnoitra, they clearly state that they are Cuatro and Cinco Espada (meaning the 4th & the 5th in Spanish) while others like Grimmjow and Aaroneiro state that they are respectively Sexto and Noveno Espada (the 6th and 9th).

Shinigami and Ryoka Counterparts
Several of the Espada are very similar to certain shinigami and Ryoka, either their roles, personalities, or relative power level; Grimmjow, Zommari, Stark, Barragan, Halibel, Nnoitra, and Szayel are Ichigo's and Byakuya's, Kyoraku's, Yamamoto's, Soifon's, Kenpachi's, and Mayuri's respective arrancar counterparts due to their strength, personalities and roles (Szayel and Mayuri are both scientists). Yammy is Lieutenant Omaeda's counterpart due to their dimwitted and somewhat oafish personas.