Disclaimer: I don't own Bleach.
"The Dawn of Shinigami began with the king from the east, and the queen from the west.
"At that time, he was not a king, nor she a queen - he was simply a man, known as Chibaniki Shiku; and she was simply a woman, known as Zohoin Toba. Neither came from prestigious families or nobility, for at that time, no such things existed. He, a butcher; she, a gardener; each had a family that they loved and supported.
"Shiku lost his family to the monsters of the night; and in his suffering agony, was forced to bury his wife and thirteen children. As his toil bathed in the blood of his loved ones, their life leaking forth as he entombed them in the earth, their lifeblood seeped into his skin and merged with his core. To a lesser man, the taint of such tragedy would stain their sanity, leaving a man broken and hollow - but this man was pure. His mind, soul, body, and heart loved his family with burning white purity, and thus his essence could not be stained - so the white ribbon of this soul, faced with the blood of his most cherished, chose to dye itself a crimson red. The butcher reached for his largest blade, and willed his consciousness into it; so that it would serve him for all time.
"Toba lost no one, for her family was not of those her kind. She lived alone. Her family was her flowers. She tended to them every day as their mother, nourishing them and bringing them forth to their greatest potential, be it the stunning beauty of fresh irises, or the deadly potent poison of the nightshade. To Toba, all that existed was because the world of souls found in it a purpose, and thus she reveled in the care of all flowers. Her heart was sad, for it was lonely; but she knew of no one else - for she thought the flowers birthed her, and to them she would return.
"Shiku was man of pure heart, but new purpose; and so he set out to fulfill that mission that he had been gifted. For days, weeks, years; he passed through the world of souls, cleansing the horrors of the night, the monsters with holes. His journeys brought him towards the setting sun, which rose from his home in the east but set over Toba's garden in the west.
"Eventually, he found her; and she loved him for she had met no other. Her loneliness drew forth his loneliness; and together they banished each other's solitude. Thus, their souls knew each other as Gods of Death - he who had escaped it, and she who relinquished his pain from it.
"One day, Toba feared for Shiku's safety. She pleaded with him to forge her a blade; but he could not because her ribbon was white. She pleaded and pleaded, but it was to no avail; all until she asked his blade to share its will with her heart. Where Shiku could not, his blade could; and thrust forth, their ribbons intertwined; white with red and red with white, until neither could be distinguished. Crimson tied with crimson, the lifeblood of the loved flowed from core to core, and from her garden Toba took a reed; and infused with her newfound consciousness, it breathed forth life; and where the reed once stood she now beheld her own sword. From then on, they fought back the monsters of the night - she with the power of her mind, he with the power of his heart, and both with the power of the sword. Together, their strength grew, the edges of their weapons sharpened, until they mastered their blades to reflect their own souls, each to their own as is known today.
"As the nights grew longer, these first shinigami realized that their great crimson ribbons called forth the beasts from the four corners of the spirit world. Shiku called forth to Toba, and he gathered his blade and she gathered hers, and they bound them; intertwining them in soul and weapon alike. In her honor, he etched her initials in his heart as a solemn promise to protect her all his days - and called forth the power of their being through that promise, known today as legend of the Zotokai.
"The great Zotokai Spirit burst forth from the bound blades, like an entity from another universe. 'What seek ye, masters of great bond, that you call me forth on this day?' Awed by its power, they requested from the Great Spirit the freedom from the demons of the night, and so the Zotokai drew forth his awesome, mighty blade and cut a great hole in the sky. Calling forth to all monsters, his thunderous voice echoed from the garden of the west to the abandoned home in the east: 'Go, seek rest! Breed and be plentiful, and leave this place forever more!' Thus, the great darkness of Hueco Mundo was born, and the world of spirits was left to become dominated by a society of souls.
"When the people of the land heard the echoing power of the Great Zotokai and saw their nightmares flee into the rip in the heavens, they cheered and searched and searched and saught, until they found Shiku and Tobu; and donned them King and Queen for all to honor.
"Intertwined now in all aspects but one, they married and begot four children at once. Children born through parent's lifeblood, the crimson ribbon of Shinigami ran strong in their veins. Thus their followers begged of them, 'Please, O King and Queen, may we name them in your honor?' Toba knew of no names, for she had met none but Shiku; and Shiku had already named thirteen children - so they granted the wish of their followers. 'No name we know of from amongst us souls will bring glory to the Shinigami, thus we shall craft their names from your own;
behold we call to them - Kuchiki, Shihoin, Shiba, and Banzo,' and they became the great Four Houses for all time in the land now known as Soul Society.
"The King and Queen were honored, but they did not forget their origins. Shiku created thirteen armies to defend against the evils of the night - one for each of his deceased children; and Tobu branded each with a member from her family of flowers. They settled in the heart of the Court of Pure Souls, and they grew old together; but their Zotokai was never seen again."
-:-
Yoruichi finished reciting the passage, the legendary tale of the 'Origin of the Four Houses', that had been written down in four tomes that was owned by each of the four great noble families.
"Why have I never heard of this tale?" asked Rukia, surprised that as a Kuchiki, she knew nothing about it.
"It's legend and myth about the creation of the Four Houses. It's not something you would have learnt in the academy; although I wouldn't be surprised if there were some in the upper echelon of the Gotei 13 who would recognize it. Lil' Byakuya does for sure - he could recite the whole thing word-for-word, just like I did. They make each head of the Four Houses memorize it before they ascend to lead their clan."
Ichigo interjected, curious. "I suppose that would mean Shiba Kuukaku also knows it?"
"Oh, I know for a fact that she does. I remember teaching it to her, after Kaien-dono passed away." Yoruichi looked to Rukia to see her reaction, but the petite shinigami gave none.
Ichigo, who in general could hardly give a crap about fairy tales, found this whole tale quite interesting. "So, I don't get it. If the story isn't a secret, why did you have to hide the files?"
"It's the not the story, Kurosaki-san. The story just confirms what I've discovered. A zanpakutou has only two releases - a shikai, and then a bankai. But soul infusion breaks down the barriers around the limitations of a zanpakutou's abilities. It's similar to how a vaizard's inner hollow allows a shinigami to surpass his natural limitations, and how an arrancar's removal of their mask gives a hollow powers normally only available to a shinigami."
Yoruichi asked the question that Ichigo and Rukia were still rolling around in their minds. "So zotokai is a third release of a zanpakutou?"
"Not exactly. It's a third release, but it requires a pair of zanpakutou that share the same bond. In practical terms, this means two people who have a bonded soul that are capable of wielding their zanpakutou to do so."
Realization came immediately to Rukia. "I get it now - Captain Kurotsuchi created Nemu from his own soul, so he met the soul infusion requirement with her; without violating any law!"
Ichigo followed the trail of thought. "And Nemu hadn't yet achieved bankai - so that's why you hid your bankai gigai information from him. You didn't want him to have an easy way to teach Nemu how to cross that gap."
"Exactly," Urahara answered. "Only two people who possess intimate knowledge of their zanpakutou - in other words, bankai users - could call forth a zotokai, even if they had met the bonded soul requirement. If Nemu were ever able to use bankai, then Mayuri would have nothing preventing him from releasing it. However, unlike a shikai or bankai, which is an extension of the shinigami's consciousness; a zotokai is a completely sentient manifestation of the joint emotions of the two wielders. It cannot necessarily be controlled by anyone."
Rukia's eyes widened in horror. "In other words, a zotokai spirit from the two of them could be an unhinged demon, hellbent on testing the extent of its powers without regard for anything, even itself! It could want to obliterate itself and everything around it, just to see what would happen!"
Urahara nodded and took a sip of his tea. "Quite possibly. Any zotokai produced from that couple could cause havoc so great that no one would even know how to contain it. Zotokai spirits possess powers and abilities that are beyond our current understanding. They could create entirely new dimensions, vaporize existing ones - and that's merely some of the things I could think of. A zotokai could be capable of nearly anything. Unfortunately, Kurotsuchi Mayuri is too curious to avoid summoning one, even if it is extraordinarily dangerous. Of course, this is all highly theoretical. I've certainly never seen an actual zotokai, so I couldn't say anything for certain."
"So what do we do now?" Ichigo shrugged. "Did that bastard get into the files?"
"He did, and I promise you don't want to know how he got that information out of my head," Urahara shivered. "Thankfully, Rukia gave him a setback - without Nemu, he'll need time to recreate another soul-infused candidate. However, that could also mean that when he creates her all over again, he could possibly find a way to create her as a bankai user from the start. It's unlikely that such a thing is even possible, but I wouldn't put anything past that man. He is a genius, after all."
Rukia seethed inside at the mention of Captain Kurotsuchi recreating Nemu. She would not let that happen. She was about to say something, but Ichigo was one step ahead of her. "Then we don't have much time. C'mon, Rukia, let's go."
Next chapter will be out soon. Link below, that whole review thing? Yeah, I would really like it if you clicked it and provided some feedback. T'hanks! -njx