Orochimaru had made a very sound choice: if hard control was unfeasible, then soft control was certainly the next best option.
Physically restraining the "Complete Edo Tensei" version of the First Hokage presented an extremely high difficulty level. No matter how thorough the planning or complex the methods, success couldn't be guaranteed. But thinking conversely, since he had resurrected a fully conscious First Hokage, why insist on controlling him through force? Persuading him verbally was also viable, perhaps even the most viable approach.
One shouldn't view "maintaining consciousness" solely as a negative side effect. With a more open mind, less extreme thinking, even a Konoha missing-nin like Orochimaru could strike a deal with the First Hokage... Yes, Orochimaru wanted results. Whether those results were achieved through control or through negotiation, what difference did it make?
Madara Uchiha wanted to destroy the world; Nagato, at the very least, aimed to dominate the shinobi world. Be it the former or the latter, both were intolerable to the First Hokage. Even the dead cannot achieve complete detachment, and perhaps the dead care even more about the legacies they built in life. Therefore, approaching from this angle, Orochimaru easily persuaded the First Hokage.
Back then, the First Hokage had decisively eliminated Madara Uchiha when he defected from Konoha. Now, he could surely resolve the issue of a pair of Rinnegan with even greater precision and ruthlessness.
As long as the re-resurrected First Hokage saw Nagato and confirmed the threat the Rinnegan posed to the entire shinobi world, his deal with Orochimaru would be sealed, one hundred percent.
For Orochimaru, the remaining steps were simple. Without needing to worry about the Edo Tensei First Hokage turning on him, the caster, his task was to find a suitable "sacrifice" – a body capable of housing the First Hokage's power as effectively as possible, making the resurrected First Hokage as strong as he could be.
Of course, this still carried risks. Orochimaru couldn't completely trust the First Hokage's guarantee, especially with the Second Hokage present. After achieving the goal of "destroying" the Rinnegan, the possibility remained that the First Hokage might turn around and eliminate him, the Konoha missing-nin.
Furthermore, Orochimaru had no intention of actually destroying the Rinnegan; he planned to seize it. Under these circumstances, the "deal breaking" was almost a foregone conclusion.
But after considering it, Orochimaru decided such risks were unavoidable and not worth excessive worry. Regardless, his plan involved pulling chestnuts out of the fire; before securing his prize, he wouldn't fret about the heat, only whether the fire burned hot enough.
Everything hinged on the First Hokage's combat strength. Consider two outcomes: the First's victory certainly brought considerable risk, but what if the Edo Tensei First lost, and the leader won? That would mean certain death with no escape. So, since he had committed, there was no point in hesitation.
Based on this thinking, Orochimaru's first priority was to prepare a suitable sacrifice. To ensure the First Hokage's maximum combat potential, the best approach was to provide a body similar to his original one, or more simply, to ensure a high proportion of First Hokage cells within the sacrifice's body.
Cloning was too slow, leaving modification as the only option. Orochimaru wasn't trying to create another Tenzo; he just needed the sacrifice to be alive and breathing.
Two months later.
A bloated, rotting mountain of flesh mixed with pools of blood became Orochimaru's crowning achievement. Within the mass, a distorted human face was vaguely discernible. Faint, intermittent moans indicated that this thing had once been a person, once a ninja.
Importantly, it was undeniably alive.
One had to hand it to Orochimaru; he always managed to come up with something new. Judging by the aesthetics alone, the current state of this former ninja looked like something straight out of a Cthulhu mythos tale, or at the very least, crawled out of Bloodborne.
In any case, the First Hokage cells proliferated within this body had certainly exceeded the required quota by a landslide. The ninja, now transformed into a monster, certainly couldn't utilize the power of these cells. Theoretically, it was just a pile of waste material. However, even waste, utilized properly, can achieve unimaginable value.
"Almost at the limit..."
Orochimaru estimated that pushing the limits any further might cause this hard-won specimen to expire. Therefore, while the thing was still alive, Orochimaru decisively activated the pre-prepared technique formula.
Treading through the ichor, he approached the monster's twisted face and swiftly plunged a kunai, bound with a complex technique formula, into its brow. The next moment, the bloated mountain of flesh began to rapidly collapse and solidify. In the blink of an eye, the figure of the First Hokage reappeared.
Edo Tensei succeeded again. Practice makes perfect, and Orochimaru was becoming more proficient each time. He could distinctly feel that this summoned First Hokage was different from the last one. An aura of power and an indescribable sense of danger emanated from this body. Clearly, Orochimaru's carefully prepared sacrifice had been necessary.
He then repeated the process, using an ordinary ninja's body to resurrect the Second Hokage. He didn't immediately awaken them. With preparations complete, there was no need to rush. He no longer needed to chat with the two Hokage; he needed them to wake up and immediately engage in battle, seizing victory.
All preparations were made. The next step was...
All or nothing.
See? Being a mad scientist is risky. Enter the profession with caution.
The next morning.
The perennial, dreary rain fell as usual over Amegakure. Mist swirled between the high towers, obscuring the sky above. In such oppressive, desolate moments, significant events often occur.
Orochimaru walked alone along deserted passageways, his pace seemingly slow but actually swift, entering the deepest spire of Amegakure.
The moment he arrived, he was intercepted by Konan.
"Orochimaru, this is not a place you are permitted to enter. I believe you are aware of this... You cannot bear the consequences of transgression and offense." Konan had already activated her technique; a pair of paper wings spread behind her as she hovered in mid-air.
The scene held a certain air of sanctity, yet realistically, based on power levels alone, Konan by herself was not qualified to look down upon Orochimaru.
This area was strictly forbidden. Orochimaru appearing here signified betrayal. Konan had never trusted Orochimaru, so his betrayal wasn't surprising. However, she had expected him to use schemes and plots; she hadn't anticipated such a blatant, head-on betrayal. So reckless, so...
Utterly foolish.
It seemed she had overestimated Orochimaru previously.
Orochimaru had been acting furtively lately – although, Orochimaru always acted furtively, he had been extra furtive recently. Anyone could tell something was amiss, and Konan had been forced to take precautions. But who could have predicted Orochimaru would choose a "frontal assault"? It was simply unbelievable.
Blinded by excessive faith in the Rinnegan's power, Konan simply couldn't believe Orochimaru possessed any reliable trump card.
"Even losers don't stay trampled forever. Take yourselves, for example," Orochimaru drawled. "I have nothing to say to you. If possible, I'd like to speak directly with your leader. If I recall correctly, his name should be... 'Nagato,' correct?"
Orochimaru directly exposed the true identity of the supposed leader. Honestly, revealing someone's hidden past upon meeting was quite unethical. Konan, caught completely off guard, froze on the spot, unsure how to respond... Their time together as a trio was supposed to remain buried, a hidden past that was both a psychological refuge and the source of all their pain. Nagato would never permit anyone to know about it. Yet, how could it be exposed just like that?
"Is this so surprising?" Orochimaru continued smoothly. "Didn't we meet once before? I would have thought your impression of me would be stronger than my impression of you."
Back then, Orochimaru could have easily crushed the three young orphans. That sense of terror must surely be ingrained deep within them. Yet, who could have imagined their positions would be reversed now?
"So, you remembered. In that case, you can only die here." As the voice rang out, the figure of the Tendo Path, Yahiko's body, emerged unhurriedly from the shadows.
Orochimaru mentioning their past was like ripping open old wounds, like grinding his heel into Nagato's crippled leg. Nagato certainly couldn't allow Orochimaru to leave alive.
Since the decision was made to eliminate Orochimaru, Nagato held nothing back this time, deploying his full power. Although Orochimaru couldn't handle the Tendo Path alone last time, Nagato still decided to deploy all Six Paths... This was the consequence of poking the tiger.
The steady sound of footsteps echoed. Soon, at the base of the high tower, five other pairs of Rinnegan eyes appeared. Orochimaru surveyed the scene, his gaze lingering for a moment on one particular figure.
"Playing your trump card right from the start? A good habit in ninja combat... In that case, I should clarify that my reason for appearing here is not to seek death."
As he spoke, Orochimaru formed hand seals:
"Ninjutsu: Impure World Reincarnation!"
Two coffins were summoned. As the lids opened, two figures stepped out. Their movements were stiff at first, merely rigid on the second step, but by the third step, they moved as naturally as any living person.
"So, it really is the Rinnegan."
The First Hokage knew little about the Rinnegan, but upon seeing those distinctive swirling eyes, an intuition deep within told him this was it. This confirmed Orochimaru hadn't lied about the basic facts.
The Second Hokage scanned the surroundings. Seeing six pairs of Rinnegan didn't surprise him. As expected of one of history's greatest sensor ninja, he grasped the unusual situation immediately. "Brother, these are all puppets. The one pulling the strings is hiding behind them, refusing to show themselves."
How to describe the feeling? No matter how perilous the battlefield these two appeared on, it felt as if they had simply returned home. A deep inhale of the battlefield's bloody air only served to invigorate them... These two brothers were the most efficient killing machines in shinobi history.
At that moment, Orochimaru spoke, "Be careful. One of those puppets is the corpse of a rising star from Konoha."
"A rising star? Which one?" the Second Hokage inquired.
Orochimaru grinned.
"The most troublesome one."