"I think I have a good starting point." The blonde haired boy sat down on the edge of the roof, back pressed firmly against one of the numerous small raised portions which might have been battlements many centuries before.
"Now is probably not the best time to discuss such things." The other boy, bespectacled with brown hair, nearly as messy as his companion's, gave his friend a meaningful look before glancing down over the edge of the roof. Below, the citizens of the Rukongai milled about their daily activities, but in the shadow of one overhang, hiding in plain sight, was a nondescript man in dark clothing. He had not turned the page of his book for more than ten minutes. The Onmitsukido had been increasing their surveillance of the inner districts steadily for years.
"Ah, I see what you mean. It's quite warm out today, is it not? 31 or 32 degrees, I'd say." The blonde leaned his head back but kept his eyes fixed on the other boy.
"At a guess, I'd say 32. It's supposed to be a full moon tonight..." That was all that needed to be said. The brown haired boy was gone in a flash, and after a few moments to observe the Onmitsukido officer and ensure that he had not taken off after his friend, the blonde followed.
The new roof was in the mostly unoccupied forested area of the middle districts to the west of Seireitei. They had developed the secret language soon after they met. At first, it had been a challenge to each other, to match the other stride for stride on the mental playing field, but as their discussions turned to deeper and darked subjects, it had become a standard they used to avoid unwanted eyes and ears.
He hadn't even told Yoruichi or Tessai about the boy he had met who could keep even his great mind sharp and sometimes worn out. He thought it better to keep his intellectual company to himself for as long as they were going to discuss things that smelled of treason.
"So, what is this starting point of yours, Kisuke?" The brown haired boy relaxed against a tree, pleased to be away from all the masks they had to wear within the walls of their home.
"Nature will always seek balance." Kisuke Urahara replied simply. His companion considered for a moment, then nodded.
"I like it. I was leaning toward something along the lines of true balance opposing free will, but yours allows a lot more flexibility."
"High praise, Sousuke." Urahara grinned. "Care to start?"
"Hollows are natural. They progress naturally from Pluses, and Pluses progress naturally from Humans."
"Quincy as well. I think Quincy flow as naturally from Humans as Hollows from Pluses. Perhaps souls were simply meant to come to an end eventually? There is a sort of balance in oblivion, after all. Humans would die and become Pluses, as Pluses were reincarnated and become Humans. Hollows would devour and devour, bringing the scattered souls together into a single target, then Quincy would destroy them, until eventually nothing remained of any of them."
"There is an alternate hypothesis. We are simply mistaken about the nature of the Quincy, specifically about what happens when they destroy a Hollow. If we assume that Humans and Pluses are a balance of their own, constantly flowing back and forth between each other, and that they progress naturally to another pair of balancing opposites, then we should also be able to assume that the result of a Quincy killing a Hollow should mirror that of a Hollow killing a Quincy."
"Something about the Quincy reacts to the reiryoka of Hollows, making them almost instantly lethal, but the souls are not destroyed… They simply become pluses, as is expected… So, to mirror that, when a Quincy kills a Hollow, it would become a Human once more?"
"I believe that would be a logical acertion. Now, we must ask, where to Shinigami come in? We exist, therefore we must have a place in the balance. We come from souls, but are as much the opposite of Hollows as the Quincy. I would propose that we are the result of Quincy reiryoka invading an ordinary Plus. The power manifesting differently within us as the generations go onward."
"From that, we would have to assume that there exists a sixth form of creature which results from Hollow reiryoka entering into a living Human. I have heard rumors of such a thing, but none of my research has uncovered anything of the kind."
"What of your research on the Soul King?"
"There are stories of the Right Arm of the Soul King in the distant districts of the Rukongai. It is said to represent stasis, stagnation, tradition. Perhaps the Left Arm is the opposite, representing progress and evolution..."
"The Right Arm, then, would be the Hollows, while the Left Arm would be the Quincy? The Soul King, by extension, would have to be the fusion of lethal opposites. A creature in whom both Hollow and Quincy nature could reside, which in turn would bring the presence of both Human and Plus, as well as Shinigami and this sixth kind."
"There is a certain elegance to it, don't you think? The Quincy will replenish naturally from Humans as surely as Hollows will always replenish from Pluses. As long as there are Humans, there will always be Pluses, and as long as there are Pluses, there will always be Humans. And even more, Shinigami and the sixth kind will also follow naturally."
"So, why are we taught that the balance of the world is so fragile that we Shinigami alone can maintain it, else all of creation would fall about our ears? I think that there is a certain darkness that is bred in lives that stretch on for too long. Moving through the cycle is natural and necessary. To purge that darkness and rekindle the light inside of us. The Soul King acts as the keystone by filtering that darkness… By ensuring that the cycle continues."
"The Captain Commander has lived for more than 2000 years. If the legend of the Sealed King of the Quincy is accurate, then so has he. What of the Hollows and the sixth kind? They have no great leaders from two millennia ago… Where is the balance in that?"
"Perhaps that balance has been broken by us… By Yamamoto and Yhwach before they fought one another and Shinigami rose over Quincy. Maybe their mutual hatred of Hollows is the only reason that they had not declared war on each other before then. Maybe they killed the equivalent among the Hollows. Maybe even among the sixth kind as well."
"If that is the case, then the balance really is in danger, and not from Hollows. From Shinigami and Quincy… Shouldn't the Soul King step in to rectify the imbalance? Shouldn't that filter recognize that those two have lived too long and have begun harming the balance in a way that will take a true catastrophe to correct?"
"Maybe he can't… Maybe he saw the strength of the balance and cut of his arms to lend strength to the two sides, and so lost his ability to step in and set things right. Perhaps the Right Arm belongs to the Shinigami now, with the fall of the Hollow Lord?"
"How can it be corrected, then? Either the Soul King must be replaced, or the balance must be restored by those who dwell here within it. And to do that… It would require the death of both Yamamoto and Yhwach. It would require the return of the Right Arm to the Hollows and the establishment of a new king among them. It would require a change in the paradigm of all six groups. And I fear it would still require the replacement of the Soul King. Someone willing to give an arm to the Shinigami and the sixth kind to complete the balance."
"But there is no one capable of taking his place. They have to be both Hollow and Quincy." Sousuke looked at his sketch in the dirt and blinked. "Maybe there is a way..."
"What are you thinking?" Kisuke looked at the scribbles as well, unsure what sudden inspiration his friend had drawn.
"I think… If Hollow Reiryoka were sealed within the soul of a Shinigami and then that soul mated with a Quincy, or alternatively if one of the sixth kind were sealed within a Quincy and mated with a Shinigami, then the offspring would be able to contain the contradictory natures. Then it would be a matter of drawing each nature out to its full extent without allowing them to tear apart the host."
"A Hollow sealed within a Shinigami… Is such a thing even possible?" Kisuke shook his head. "It would be dangerous… They are on opposites ends of the evolution of a Plus. There is a little Quincy within Shinigami, after all. Not enough for Hollows to be lethal to us as a general rule, but having one within our very soul… There is every chance the host would be torn apart."
"Something to break down the barrier then… Something that could bridge the gap and allow one to fully step into the domain of the other."
