They basically don't have any traditional concept of good and evil. When they do things, there's zero psychological burden at all.
Even if you put that concern aside, in the future he might get along extremely well with Squad Zero, to the point where both sides are so close they're basically wearing the same pair of pants… but as long as he thinks about how the weakness of his Bankai is always being held in the other party's hands, his heart can't help but feel uncomfortable.
He has to leave himself a backup plan. At the very least, he absolutely cannot use an officially issued Asauchi.
He needs to find a suitable weapon himself to use as a carrier, use that to evade the Sword God's perception, and then look for a chance to see whether he can complete the training for Shikai in another world.
'You, Great Monk, claim that you named everything in Soul Society, so you can see through all true names. That really is impressive. But if I take out a Zanpakuto that was forged in another world, also named in another world, and even fused with energy from another world, how would you deal with that, I wonder?'
"Akame ga Kill", Soul Society, "Akame ga Kill", Soul Society…
After going through the tedious process of traveling between worlds, Iori didn't cut any corners. He completed every single step without missing a beat, successfully resetting the time flow between the other world and Soul Society back to a one-to-one ratio. Only then did he feel at ease enough to sleep soundly.
The next day, he originally planned to go to class, but right as he was heading out, he remembered that the academy had given him leave "yesterday." He was still in a recovery period, so there was no need to go to class after all.
With this sudden free time, there wasn't much to do. After thinking it over, Iori went to see Mayuri Kurotsuchi again, to urge this mad scientist to hurry up and finish the "matter-to-reishi conversion device." Even if the output was a bit low, it didn't matter, otherwise, the things he obtained in the other world wouldn't be able to be brought back to Soul Society.
At the same time, he also placed an order for a drug reverse-engineering project, though he didn't specify exactly which drug it was, only telling Mayuri to wait for further notice.
Mayuri was extremely dissatisfied about this.
As a researcher, even though there was something wrong with his head and his moral standards were practically nonexistent, his sense of pride was not weak at all. He was not some mediocre person who would let others summon him at will and obediently do their bidding.
He did enjoy researching all kinds of things, but only on the condition that the project interested him.
He couldn't handle following rules step by step, and he hated it most when others tried to make plans for him, as if treating him like a tool instead of a free soul.
In the past, he had clashed with the Seireitei multiple times and been imprisoned. One reason was that he walked an evil path and his research was far too dangerous. The other was that he refused to conduct research according to the ideas of those big shots, and instead chose projects that looked inexplicable to others.
The upper ranks wouldn't waste resources on those kinds of studies, so Mayuri could only take on private jobs to earn some money to subsidize his main work, and he received quite a few clients like Iori.
Given his personality, the fact that he was willing to help at all was already pretty good.
Who would've thought that every single one of these people, without exception, were greedy ghosts and complete amateurs, spending ten thousand and wanting to get a hundred thousand's worth of results, constantly urging him on and questioning him. It was seriously unbearable.
Today, Mayuri's emotions had already piled up to the brink of eruption. Even though Iori counted as a fairly high-quality client, he still wanted to vent hard, "I'll settle the remaining payment right now. Starting from today, you have six days. For every day earlier you deliver the conversion device, I'll add a few more percent to the payment."
"The reverse engineering of that drug counts as a separate commission. From the day you finish the conversion device, you get three days. For every day earlier you complete the antidote, I'll pay a few extra percent above market price."
"So? What do you think?"
Mayuri suddenly felt that this young man, Iori, looked quite pleasant to the eye, spoke especially nicely, and clearly had great qian-tential. As an elder, he really should support young people more.
As for what Iori wanted the reishi conversion device for, or where that modification drug came from, the mad scientist had zero interest in asking.
Mayuri, 'Isn't it perfectly normal to be carrying eighty or a hundred kinds of contraband on you?'
"By the way, since there's technology to convert matter into reishi, is it possible to do the reverse, turn spiritual bodies into matter?" Iori asked casually, as if it were an afterthought.
"Didn't I already tell you about gigai?" Mayuri didn't care much. "That research isn't finished yet."
"No, I'm not talking about that kind of artificial body you wear like a coat. I mean turning a Shinigami itself into flesh."
"..."
Mayuri stopped what he was doing and looked at Iori in surprise. Iori, as always, wore a harmless smile.
"I'm just asking."
"As far as I know, no."
Mayuri said coldly, but perhaps driven by a scholar's urge to show off, he explained a bit more.
"If it's just lifeless objects, then whether it's materialization or reishification, it's not that difficult. But 'Shinigami' are different."
"Humans can be turned into reishi, right? Then why can't Shinigami be materialized?"
"No!"
"Turning humans into reishi is taboo, but technically it's completely feasible."
Mayuri said without any scruples. "But have you ever thought about the difference between humans and Shinigami?"
"...An extra physical body?"
"That's right. Humans simultaneously possess an 'outer (flesh)' and an 'inner (soul).' If they want to come to Soul Society, they just need to convert their physical body into a reishi state."
"But Shinigami don't have such a convenient body. What we possess is only the 'inner (soul).'"
"If we want a true physical body like humans have, then we need to turn the 'inner' into the 'outer', that is, materialization..."
"And here's the problem. After our soul materializes into a physical body, where inside that body do we find another soul?"
Hearing this, Iori's body trembled slightly, a dazed look flashing through his eyes.
Mayuri didn't care about his reaction and continued talking to himself.
"I once looked through the library of a certain noble family. In the past, the Seireitei definitely conducted related experiments, but not a single one succeeded."
"The souls used as test subjects either turned into walking corpses or directly collapsed and scattered."
"In other words, this violates objective laws. Just like how material bodies cannot exist in Soul Society, it's one of the rules that maintains the operation of the three realms."
"...So according to what you're saying, if a Shinigami wants to become 'human,' they can't directly materialize, but instead need to find a body that can serve as the 'outer,' and then let themselves become the 'inner'?"
"That's exactly the technical principle behind gigai!"
Mayuri grinned, looking eerie and terrifying. "Do you want to know what materials gigai are made from?"
"..."
In short, since Shinigami are pure spiritual bodies, they can't just conjure up an extra shell out of thin air. So they use artificial objects as 'clothes,' and then wear them.
After figuring this out, Iori shook his head. "Looks like this isn't suitable for me. In the future, you don't need to keep an eye on gigai technology for me anymore."
What Iori wanted was a physical body that truly belonged to him, one that could freely switch between flesh and spirit, without weakening his strength.
Not a gigai that was basically like possessing a corpse.
He had originally thought that, given the special nature of Bleach, maybe soul materialization would be relatively easy, and he could obtain a physical body without much trouble.
But now it seemed that, in Bleach, this was a dead end… no wonder that even captain-level Shinigami in the original story needed gigai to masquerade as humans when they came to the world of the living.
Looking at it this way, the Type-Moon worldview's Third Magic fit Iori's requirements much better… but right now, he had no way to go to the Type-Moon world.
And even if he did go, he'd still have to fight in a Holy Grail War. With his current strength, trying to survive until the end… honestly, that wouldn't be easy.
"Things in the world really aren't that simple!"
Iori laughed freely. Even though he felt a bit frustrated, once he thought it through, he didn't really care anymore.
Same old saying, there was still a long future ahead, full of infinite possibilities. How could he get discouraged just because of a temporary setback?
'This kid…'
Mayuri hadn't expected Iori to adjust his mindset so quickly. He looked at him in surprise, clicked his tongue, then withdrew his gaze and continued his own work.
He suspected, no, he was one hundred percent certain, that Iori was a restless troublemaker, probably plotting some earth-shaking conspiracy in secret, something unfavorable to the Seireitei.
But what did that have to do with him?
Mayuri didn't care. As long as it didn't affect the balance of the three realms, it was fine. Without the three realms, he wouldn't even have a place to conduct experiments.
Besides, even if the entire Central 46 dropped dead, he wouldn't furrow his brow in the slightest. He might even be happy about it for a while.
Seeing that Mayuri had stopped talking, Iori also lost interest and prepared to go home, but he still felt a bit uncomfortable inside.
How should he put it, Mayuri's attitude just now, that look of seeing right through him while being full of disdain, as if he were the only wise person, made Iori feel somewhat depressed.
"Oh right, about the Shinigami materialization we just talked about… the reason it can't be done is, simply put, 'a Shinigami with only one soul can't separately convert a physical body and a soul', that is, '1' can't be split into '1 + 1,' right?"
"Hah? You're still here?" Mayuri turned his head back scornfully. "Yeah, I explained it very clearly. What part don't you understand?"
"No, no, no. I just suddenly had an idea."
Iori acted like a good student who loved learning and said casually, "Since '1' isn't enough, wouldn't it be fine to turn '1' into '2'?"
"What kind of nonsense are you spouting… huh?" Mayuri's eyebrows twitched, as if he'd thought of something. "What do you mean?"
"As far as I know, there exists a mental illness called 'dissociative identity disorder.'"
"Although it's just different facets created by the deep consciousness for various reasons, in essence it still belongs to the same soul."
"But is there not a possibility that it's not just consciousness and personality that can split, souls can split too?"
"If a Shinigami were to split their soul into two parts, wouldn't that allow them to create both the 'outer' and the 'inner' at the same time?"
"!!"
"Going even further, if a soul could be split into more parts, or if multiple backups could be copied through some kind of technology, wouldn't it be possible to constantly switch the main body? Even if one soul is destroyed, another backup could be activated, allowing knowledge and will to continue being passed on?"
Iori thought for a moment. "If there were always backup souls, wouldn't that basically be eternal immortality?"
"How fascinating. Infinite time would mean infinite energy to observe this world… after a thousand or ten thousand years, the entire universe would probably hold no secrets from them at all, right?"
"Y-you, you..."
"Alright, I'm going back to cook now. Bye-bye~"
"Wait! Kid! Explain yourself clearly!"
Mayuri chased him out the door, but Iori had already left using Shunpo, leaving the blood-pumping mad scientist to rage helplessly.
"Come back! I'll even refund your money if I have to!"
———
That felt good, that felt really good. This topic alone would be enough to keep him researching for decades~
As for whether following this path would lead toward becoming "Aozaki Toko," or learning from "Voldemort" or "Orochimaru"… what did that have to do with Iori?
He was just an honest, law-abiding substitute Shinigami, speaking on impulse, that's all~
That said, if Mayuri really did manage to produce some results, that wouldn't be a bad thing either. No matter what he researched, Iori would unceremoniously take it as reference material and turn it into nourishment for himself.
Of course, Iori wasn't crazy enough to actually split his own soul like Voldemort. His main purpose was still to study enemies.
He clearly remembered the final BOSS in Bleach, Yhwach's ability, which was related to soul splitting (distribution).
He didn't expect Mayuri to figure out Yhwach's true nature, but with more research in this area, maybe when the time came, he could spot some clues and make a few magical little tools or something.
The process by which the protagonist group defeated Yhwach in the original work was honestly unreliable. Iori felt it was better to have a few more cards in hand…
———
Two days earlier, Iori had agreed with the first-generation captain, Saito Furofushi, to ask her for guidance on Shunpo techniques. At the time, both of them were in high spirits, and with alcohol in their systems, they made the arrangement carelessly. Looking back afterward, they hadn't clearly specified the time or place at all.
Iori had no way to contact Saito, and as a substitute Shinigami, he couldn't freely move around within the Seireitei either. All he could do was wait for Saito to come find him.
However, judging from that expeditionary captain's unreliable demeanor… she might have already forgotten about it entirely.
Iori didn't have high expectations to begin with. After returning from Mayuri's place, he went to the nearby Rukongai to pick out some gifts.
As the saying goes, even a hero can be brought low by a lack of money. Since all the money he earned had been spent on Mayuri, it was time to meet with Shunsui and loosen up his finances a bit.
Kyoraku Shunsui.
A figure who could absolutely be considered a big shot in the Seireitei.
In terms of bloodline, he was born into an upper noble family, with a hereditary martial house name, second only to the Five Great Noble Families.
In terms of lineage, he was a direct disciple of Yamamoto Genryusai Shigekuni, and one of the two most favored students among the old man's many disciples.
In terms of strength, he ranked among the captains of the Gotei Thirteen, and had mastered Bankai for over a hundred years (at this point in time).
Whether it was wealth, looks, knowledge, or manner of speech, he fully lived up to the title of "noble," completely different from those who were nobles in name only.
Yet, regrettably, such a man, perfect in every respect, even more overpowered than the future Byakuya Kuchiki, had a rather flamboyant personality. He handled affairs casually and lazily, and even started writing romance novels back in his youth.
He was a true artsy youth and a wandering playboy, completely out of sync with the Seireitei's overall solemn atmosphere.
Because of this, the Captain-Commander had scolded him countless times, but even the strongest Shinigami couldn't make Shunsui change. And so, from top to bottom, the Seireitei regarded him as an "excellent but somewhat regrettable" man.
But Iori got along with him for no clear reason.
Maybe it was resonance between fellow creators.
Putting his illustrious status aside, Shunsui himself was a very easygoing good guy. Despite being a noble, he loved frequenting taverns in Rukongai, and could genuinely enjoy the games, songs, and dances of the poor.
When Iori first met him, Iori still looked like just a half-grown kid, but Shunsui could patiently listen to him speak.
As for how the two of them gradually became more and more in sync after that, eventually becoming close friends despite the age gap… that was another story entirely.
If Shunsui hadn't been willing to help, Iori probably wouldn't have found a way to publish his novels, nor would he have been able to secure his royalties.