Itachi was fascinated by the prospect of two different people possessing the same Zanpakutō, not for any other reason except for plain studious curiosity.
The phenomenon was already more rarer than possessing dual Zanpakutō as he had never heard of the instance of two people sharing the same Zanpakutō spirit. What did that mean for Zanpakutō? What did that mean for the souls of Shinigami?
He first thought to ask either Shunsui or Unohana but decided against it in favor of asking Yoruichi who he deemed to be more knowledgeable about matters concerning souls.
Even though he was fascinated by the discovery, it might not necessarily mean a good thing. The fact that two completely different and unrelated souls could share the same spirit, if nothing else was just as prospective as it was unnerving. Especially if there was no precedence to it.
He found Yoruichi in the Stealth quarters, seeing her already staring in his direction before he landed.
"I didn't think you would be coming today. Something up?" She waved her subordinates away the moment Itachi's feet touched the ground.
She never found out what Itachi had done that had made the Onmistukidō also deify Itachi.
"Something interesting came up with one of my students and I was wondering if you might know something about it."
"And that's why you personally came over?" She eyed him sceptically. "This must be interesting indeed."
"Have you ever heard of two souls possessing the same spirit?"
"I don't follow."
"Two separate individual souls sharing the same Zanpakutō spirit." He reiterated. She looked surprised, taken aback by the express of his words.
A small frown came on her face as she thought it over before giving him a soft shake of her head. "No, I don't think I have. The idea itself is strange. How did that happen?"
He gave her the brief rundown of what he knew, which wasn't much considering he just found out a few minutes ago, and just like he was, she was stumped.
"And you can't even tell the difference with your eyes? Now I really have to see this kid. Who knows? Maybe they'll be a monster like you someday." She said with an amused tone, like she was seeing the unearthing of a new gem she'll get to play with in time.
Itachi saw the budding of a gleam in her eyes but said nothing. At this point he was already used to eccentricities, but that did not always mean he had the resolve to endure them all the time.
But the fact that even Yoruichi had no idea what this must mean meant that he'd exhausted his avenue of reliable information.
He was about to leave when Yoruichi called him back.
"I might not know anything about what's going on with your students but you should ask Kisuke. If nothing else, then he'll be extra motivated to find you an answer just based on how interesting your students are."
"Thanks." He nodded at her.
"Hm. I'll catch you later."
He made his way to the 12th Division and no sooner had he arrived that Kisuke came out to meet him.
"Ah. Captain Uchiha. What a glamorous surprise to find you at my doors of all places."
Like always the reluctant Captain wore an easy smile on his face which did nothing to hide the expectant gleam in his eyes.
The man mirrored Yoruichi's antics but with the edge of his flair that all but showed just how annoying he would be to deal with. For a moment, Itachi silently appreciated that he didn't have to deal with two versions of Yoruichi every single day.
"Just some inquiries if you're not too busy." Itachi replied as he followed Kisuke into his office — or small-time workshop as it seemed.
"So what is it that our very own Captain Uchiha wants to inquire from lil 'ol me?"
Itachi ignored the frivolity in his words and straightly asked after the reason he came.
Kisuke listened to him with rapt attention, and just like Yoruichi, Itachi could see the gleam in Kisuke's eyes growing brighter the more he went on.
"Two souls sharing a spirit. Quite a breach no?" Kisuke stroked his chin, finally looking serious besides his laid back posture.
"Hmm, as far as I know of, such a case has never happened and that is either a good thing or a bad thing when it concerns souls."
"How so?"
There was a forming grimace in Kisuke's face as he replied. "Well, if it's a new thing then you have a whole level of scrutiny and bureaucracy to deal with, which is not so bad if said state is not inherently bad in nature."
"But..."
Kisuke sighed. "But if it's a bad thing and no one knows about it, well then...."
"It's forbidden." Itachi completed.
Kisuke actually laughed, but it was a brittle thing. He suddenly looked as if he was missing his time in exile where he never had to deal with red tapes and taboo laws.
"The thing is, Soul Society at its core, is not that welcoming to things that don't fit in a mould. A mould that is predictable."
"I understand, Captain Urahara." Considering the things Soul Society had hidden and never made public knowledge, even to higher-up clan members, it made it unsurprising if he later found out that something like this was considered taboo.
And the worst part of it all was that he understood. A brittle and volatile structure like the Seireitei and Soul Society as a whole had to function on strict laws that were kept and steadfastly upholded by all those under it, no questions asked.
Soul Society was a militaristic society, so he understood.
"So what do you think? Will my students risk stepping on toes with this development?"
Kisuke levelled him a languid stare, one that was equal parts sarcastic and rueful. "As a Captain, you have an unusual history of dancing too intimately close to breaking Soul Society's laws, what do you think?"
Itachi would have loudly groaned if it had been in line with his character but instead he chose to frown. The answer was obvious, and obviously one he did not like.
Kisuke saw the deep pondering that crossed Itachi's face and sought to throw him a hopeful bone.
"Right now we're just entertaining the worst parts. Maybe nothing bad will come from two Shinigami sharing a single Zanpakutō spirit." Yeah, he didn't believe that sentence the moment it left his mouth and judging from Itachi's dry look, neither did he.
He wasn't exactly wrong per se, but neither of them were overly optimistic people. The worse case scenario was always easier to picture and it acted as the perfect scale for making risky decisions.
"Regardless, the decision remains with your student." He directed a look, one that Itachi fully understood.
Those who were smart were lucky enough to understand that their Zanpakutō spirit was more than just an extension of them, it was the found on which their souls as Shinigami was built on. Telling either Kusaka or Tōshirō to give up that part of them was simultaneous to asking them to kill off a new friend, even if they would fail to understand it right now.
"I'll talk to them. At this point I can't afford to affront Central 46 in any way. Not for the next decade or two at least."
Kisuke quirked a brow at him. "You know, most Shinigami don't really plan out a schedule on what time is appropriate to butt heads with Central 46."
Itachi didn't reply. This was just another complication to him, a delicate one at that. Some might say he was being too paranoid but being the leader of the Onmistukidō didn't leave him too much avenue for optimism. He alone knew just how much things quickly got dark when people were apprehended by his Shinigami, a good number of them were for crossing invisible lines.
Moments like these were times he started doubting himself, where he started debating putting duty before morals. Sometimes it made him feel like he was back in the cog, unknowingly spinning in the same circle all just to move a machine he had no idea of.
Kisuke might be right – that was good – or Kisuke might be right – and that was bad – but whatever it was, it would put his students in the crosshairs of Central 46.
He stood up and thanked Kisuke for his time but the Captain just looked all the more suspicious.
"You definitely got something on your mind. Mind sharing?"
"I still don't know."
"Of course you do." Kisuke shook his head. He knew this type very well. It also spoke of just how similar Itachi was in character to him and Yoruichi. Well, they did say something about birds and feathers.
"A word of advice if you will," Kisuke stared at him with sharp eyes, a rare intensity Itachi ever got to see from the ever smiling Captain. "Whatever you do, don't try to go against Central 46. You are frankly not strong enough to do so."
They both held their eyes for a few seconds before breaking it off at the same time. Itachi turned around to leave, posture and presence as calm as it had been since the beginning.
"I wasn't planning to." He said as he left. 'The Central 46.... More like Soul Society.' He thought. He understood loud and clear Kisuke's warning.