Please note that Stand in Heaven takes place immediately following chapter 182 of the manga. Spoilers up to and even beyond this point are expected, and this should be kept in mind when considering joining this community. "Since the beginning, no one has ever stood in the heavens. Neither you, nor I, or even God himself. But that emptiness in the throne of heaven will be filled from this day forth. I will be the one to stand in the heavens."
Soul Society is in a state of recovery. After the infiltration of the ryoka, the rescue of Kuchiki Rukia, and the revelation of Aizen Sousuke's plot, Seireitei now works toward finding some order in the chaos. Injuries need to be tended, officers need to be prepped, information gathered and disseminated. Most importantly, plans need to be made to prepare for the traitor's move. While Aizen's true intentions are not yet known to the Gotei-13, that he must be stopped is unquestioned by almost all.
In the world of the living, the Karakura rescue group has returned, triumphant yet with the inevitable air of defeat. Their mission had been accomplished--Kuchiki Rukia's life had been spared--but the events that had unfolded before their very lives left an almost bitter feel with the group. Now, back in their own realm, they attempt to slip back into their lives, the knowledge they've gained heavy in their thoughts. This fight is not their own, and yet each waits, almost on their edge of their seats, for any evidence that the shinigami and their traitors have collided.
Unbeknownst to the inhabitants of the town that had already seen so much battle, Karakura would, once more, bear witness to coming violence. For the hougyoku is mature, and Aizen is breeding his army. His ranks of Arrancar each have their missions; those older, less powerful, are to descend into the living world and destroy every hint of reiatsu they can detect, leaving nothing to stand in Aizen's way when he finally decides to take the human world. His elite, the Espada, are being bred to take Seireitei, more powerful Arrancar designed to fight the remaining members of the Gotei-13.
For, from his throne in the heavens, Aizen can clearly see the flaws inherent in the system that governs the shinigami. Too much room for dissent, too much chaos and not enough order--the Gotei-13 fail as a whole for the simple fact that none of the captains can ever agree on anything. Certain that a new system is needed, Aizen plans to destroy all remaining evidence of this governing body and replace it with his own, leaving the Arrancar to reign over the dead.
The shinigami are not the only threat to this new system; there exists another faction, one so discreet that few know of its existence. This may in part be due to the almost hermitic lifestyle that they lead.
An imperfect creation, shinigami borne with a Hollow inside of them, that while flawed may threaten Aizen's intent to take the human world. He knows that they are in Karakura, and he plans on using his Arrancar to destroy them before they get the chance to oppose him.
What Aizen does not know, however, is how well-informed the Vizoreds truly are. His assumptions that their withdrawn tendencies would leave them open for a surprise attack are wrong--in reality, the Vizoreds know of Aizen's defection from the shinigami, know about the hougyoku, and know what he will use it to create. The details of his plan remain a mystery to both shinigami and Vizored alike; however, each side sits, flanking Hueco Mundo, holding their breath as they wait for Aizen to make his move.