History
The Espada loosely formed a very very long time ago as a fight club of sorts. In this huge section of sand dune desert there was an impossibly large and lone mountain that stood up, a rare sight for such a landmark really. Of course, Hollows and Arrancar congregated there due to it being something
different and of course personalities and such clashed due to that. Fights broke out, people fought over the rights of the mountain and who would be the one to have it or just to enjoy its rather regal and upstanding mountainness.
This went on for a long
looong time, until one day a rather enterprising and powerful came up with an idea. They beat the asses of all the beings that gathered there and forced them to become its servants. For reasons it didn't know, the being came up with the name Primera for itself and then named the next strongest down from there on in this weird language that shouldn't exist at this point in time.
That leader lasted a while, but it wasn't really a true group. It was more like a gang or bandits really that hung out by this mountain, fighting and beating up others. Over time the leaders were beaten and killed, someone else replacing them whether from inside of the ranks or just a random strong monster that wanted to see the mountain and ran across this group.
Some had bigger dreams and wishes than others, slowly but surely making buildings and homes near the mountain as they hollowed it out over time. At some point the Espada, as they were becoming known, began turning aside hollows due to how weak they were compared to arrancar and slowly but surely their influence and power over the sands grew.
Eventually though a powerful arrancar was brought to the Espada, who had begun to search out and gather them together for subduing. They swore fealty to the Primera... and then began to plot. Having large dreams, the Arrancar waited until the right time to take over and steal the power of the Espada for themself.
About three thousand years ago they did, taking them over and renaming their numbers. From then on, the Corona would rule them and the Primera merely their second in command and on down. This person is currently known as Saraiyu Sorainu, the Corona herself. Over the many years, they have done countless campaigns and collected many lands under her belt as well as the most powerful and interesting Arrancars (and a few hollows) she could find. The Espada were consolidated and then moved out to the other parts of the Endless Desert, becoming more than just thugs and instead more like rulers.
Many Espada have come and go under their reign, either being killed for treason or leaving at times... Recently, as in the past thousand years or so, the Corona has seemingly settled down a bit more after their bloodthirsty reign and control grabbing, however they are definitely times when that bloodthirsty and cunning nature rears its head despite how 'calm' they seem at the moment.
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