The Espada and the Pivaron Espada

The Espada (十刃, (エスパーダ), Esupāda; Spanish for
"Sword", Japanese for "Ten Blades") are the
top-ranked Arrancar in Sosuke Aizen's army of Hollow-Shinigami hybrids, are the
most powerful Hollows under Aizen's command, and are the main rivals of the
Gotei 13.

Those among the Arrancar
that excel in killing power are chosen and favored according to their
strength are assigned a number from one to ten, collectively referred to
as the Espada, holding absolute power and authority over the Numeros.
At any given time, the Espada has a nominal composition of ten
members, all hand-picked and ranked by Aizen himself. Along with Aizen, Gin
Ichimaru, and Kaname Tosen, the Espada as a group possess comparable strength
to Soul Society's Gotei 13 Shinigami captains.
At the time of the group's introduction, the Espada consists of
nine males and one female. Each Espada member is chosen for their
superior combat ability and then assigned a number from 0 to 9 (0 being
the strongest), originally thought to be ranged from 1 to 10, that
indicates their rank and relative power level, which is tattooed
somewhere on their body. For instance, Grimmjojaquez's is located
on the right side of his lower back and Coyote Starrk's is on
the back of his left hand.
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. 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 searching for the Vasto Lorde.


Being Aizen's most direct subordinates (not counting Gin Ichimaru and Kaname Tōsen),
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 and the
location of the Hōgyoku
within Las Noches. 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.
According to Dordoni,
Aizen treats them as tools to do his bidding, but nonetheless, he
wanted to take back his position as an Espada to once again be close to
Aizen. In accordance with this, Aizen is not at all distressed over the
deaths of the Espada and calmly congratulates the intruders in Las
Noches for their victories against the Espada as he leaves for Karakura
Town.
Their immense amount of power and leadership status among the
Arrancar also grants each Espada the authority to exert command over
Aizen's other forces within Las Noches: the Números, the Exequias, and their
own Fracción.
There seems to be a sort of hierarchy among the Espada; a higher-ranked
member apparently can give orders to lower-ranked members. This is
demonstrated when Aizen orders Ulquiorra Cifer to
kidnap Orihime Inoue; the
Arrancar led by Ulquiorra included Luppi Antenor (the
then-sixth Espada), Yammy
Llargo (Arrancar 10/ Cero Espada), Grimmjow Jaegerjaquez,
and Wonderweiss Margela
(unassigned). Various missions usually involve one or more Espada
operating together, with the most senior member exercising command over
the others; typical, non-combat missions, such as searching for the Vasto Lorde and
gathering pre-invasion data in the Human world,
include a senior Espada and a lower-ranked one being sent out in pairs.
While the lower-ranked members usually have little restraint in taking
their own initiative (thus exceeding their orders), higher-ranked
members usually stick to Aizen's commands, and are often the first to
bail the others out of trouble, because in Nelliel Tu Odelschwanck 's
own words, they wish to, "prevent the Espada from losing one of their
own." However, Aizen's attitude toward the offending Espada members seem
to be one of leniency, officially forgiving them (though not without
severe sanctions) on the grounds that they are merely advancing his own
wishes.
Aside from regularly appearing in Aizen's throne room and the
debriefing room, the Espada are known to have their own quarters within
Las Noches; those that have been seen appear to have been modified to
suit the specific Espada's taste. Szayel Aporro Granz,
for instance, possesses a large building that he refers to as his
"palace," complete with a hidden, indestructible laboratory and a
changing room; Zommari
Rureaux has been shown on one occasion to await orders inside a
meditation room; Coyote
Starkk's room is designed along the lines of a lounging chamber and Aaroniero
Arruruerie 's
tower, accessed via a hanging bridge, effectively keeps out sunlight
and contains nooks and crannies for hiding cushions and other implements
whose purpose is to make his shape-shifting abilities more convincing.
According to Ulquiorra, any Espada ranked 4th or higher are not allowed to
release their Zanpakto within Aizen's palace, as their Resurreccion's released
powers are powerful enough to destroy the majority of Las Noches.


The creation of the Espada has long been one of Aizen's most
important preoccupations. While it is not specified when the Espada were
first brought together as a group, the original Espada were already in
existence sometime before Aizen's defection from the Soul Society and
acquisition of the Hogyoku. Since then, the composition of the Espada has
changed, both in membership and position.
At some point in the past Nnoitra Gilga was the 8th Espada with Nelliel as the
3rd Espada and Szayel Aporro Granz was not a member at all. During this
time Aizen frequently sent the Espada out to search for the Vasto Lorde-class
Menos.
Before his death, Aaroniero Arruruerie
was the sole member of the current Espada who was also part of the
first-generation Espada. He was also the only Arrancar from
Gillian-class Menos stock to attain a position among the Espada.


An Espada may be demoted from the group either when they lose strength
or cease to be useful to Aizen, such as Grimmjow Jaegerjaquez after his
left arm was cut off by Kaname
Tōsen. In most cases, they will be demoted to the Privaron Espada (十刃落ち (プリバロン・エスパーダ), puribaron esupāda;
Spanish for "Deprived Sword", Japanese for "Ten Fallen
Blades"), who are former Espada that have officially lost their rank
and are assigned a three-digit number.

The Privaron Espada are former
Espada who have officially lost
their rank and are assigned a three-digit number. Being former Espada,
they are far stronger than the normal Números. They reside in Tres
Cifras, which translates literally from Spanish as "Three Digits".
As mentioned by Dordoni, these former "naturally created" Espada were

rendered obsolete after Aizen began artificially creating Arrancar to
meet his own standards