Espada

The Espada (十刃, (エスパーダ), Esupāda; Spanish for "Sword", Japanese for "Ten Blades") are the top-ranked and most powerful Arrancar in Sōsuke Aizen's army. serving as the primary opponents of the Gotei 13 captains during Aizen's war.

Biography
The creation of the Espada has long been one of Aizen's most important preoccupations. The original Espada were already in existence sometime before Aizen's defection from Soul Society and acquisition of the Hōgyoku. Since then, the composition of the Espada has changed, both in membership and position.

At some point in the past Nnoitora Gilga was the 8th Espada with Nelliel Tu Odelschwanck as the 3rd Espada and Szayelaporro 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.

Outline
The Espada are comprised of ten Arrancar with exemplary strength. Members of the Espada are given a number from 0-9. Each Espada has a tattoo with their number somewhere on them, such as Grimmjow Jaegerjaquez, whose tattoo is on his lower back, and Coyote Starrk, whose tattoo is on the back of his left hand. Along with Sōsuke Aizen, Gin Ichimaru, and Kaname Tōsen, the Espada as a group possess comparable strength to Soul Society's Gotei 13 Shinigami captains.

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, chosen by them from the Números. 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 in his Espada's abilities to send them out on potentially hazardous missions, such as gathering information in the Human World, fighting Shinigami captains inside Las Noches and Karakura Town by themselves, and searching for Vasto Lorde. The Espada all together at a meeting called by Aizen. Being Aizen's most direct subordinates (aside from 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 Ōken, and the location of the Hōgyoku within Las Noches. Aizen's respect for the Espada's abilities is reflected in 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 Alessandro Del Socaccio, though Aizen treats them as tools to do his bidding, 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.

There is a hierarchy among the Espada; a higher-ranked member can give orders to lower-ranked members, such as when Ulquiorra Cifer leads a team of lower-ranked Espada to kidnap Orihime Inoue. Various missions usually involve one or more Espada operating together, with the most senior member exercising command over the others. 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, according to Nelliel Tu Odelschwanck, they wish to prevent the Espada from losing one of their own. However, Aizen's attitude toward the offending Espada members is one of leniency, officially forgiving them (though not without severe sanctions) on the grounds that they are merely advancing his own wishes.

The Espada have their own quarters within Las Noches, which have been designed to suit the specific Espada's taste. For instance, Szayelaporro Granz possesses a large building that he refers to as his "palace", complete with a hidden, indestructible laboratory and a changing room. Zommari Rureaux has a meditation room, while Coyote Starrk'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 Zanpakutō within Las Noches, nor are any Espada allowed to discharge a Gran Rey Cero as both are powerful enough to destroy the majority of Las Noches.

After Aizen's defeat and the deaths of Starrk and Baraggan Louisenbairn, Tier Harribel becomes the ruler of Hueco Mundo. However, an empire called the Wandenreich appears, and she is personally defeated by Yhwach and captured. The Wandenreich empire claims Hueco Mundo as their dominion. Grimmjow also survives the Invasion of Hueco Mundo and allies himself with Ichigo Kurosaki and his friends in order to help him fight Yhwach and the Wandenreich solely so that there can be a world left to fight Ichigo.