At around the same time, far to the north in a secret command post hidden in the Hot Water country, somewhere around Yugakure, Orochimaru was completely absorbed in his work.
Ryusei's visit half a year ago had pushed his vision further than ever.
It wasn't just the notes on bloodlines and soul techniques; Ryusei's insights had shattered the last of Orochimaru's old assumptions about what was truly possible without the right genetics and chakra.
The first thing he'd done was secure his own supply of Hashirama's cells from Danzo, methodically researching and dissecting every secret of the Senju's monstrous vitality.
He'd later acquired two strong Sharingan from Ryusei as well, already making rapid progress regarding them in his laboratory.
But the real breakthrough had come from a new source.
After mastering the highest level of juinjutsu over the course of his shinobi career as well, Orochimaru was able to break Danzo's seals and poach many Root operatives for himself, completely free of that old man's control, same way he discussed with Ryusei one time.
With their loyalty and expertise, he dispatched scouts across the Land of Hot Water, the Land of Fire, and beyond, hunting for new specimens, new secrets, thirsty for growth.
That was how he found Shin. The missing piece, the one that would finally unlock the future.
Orochimaru also made contact with a rare, unnamed clan living near Ryūchi Cave, a bloodline mutated by generations of exposure to the cave's sage energy.
These people could absorb natural energy innately.
Sage Transformation, what he called it, came as easily as breathing to them, but the price was madness.
They suffered unpredictable fits, bursts of violence, sometimes even cannibalism, but the trade-off was potential.
Their bodies produced unique fluids, allowing them to shift shape, harden flesh, or create weapons from nothing.
Eyes with yellow irises and black sclera, shifting skin and wild hair, Orochimaru recorded every detail over time.
He saw opportunity everywhere. Orochimaru perfected his knowledge of soul transmigration using Ryusei's notes, refining his own rituals for moving spirit and memory into new vessels.
But six months ago, for the first time, he admitted to himself, he couldn't just keep taking bodies at random.
Stealing a vessel like Ryusei's, or even Fugaku Uchiha's, would never be simple. Too risky, too unpredictable.
Then, thanks to unlocking Shin's unique genetics, he saw the real answer: create the perfect vessel from scratch.
It was that paradigm shift in thinking that was most crucial to the rapid rise in this world, he realized then.
Shin's DNA was a genetic treasure, rejecting nothing, accepting any tissue or organ without resistance.
Orochimaru started experiments immediately, growing clones from Shin's tissue as a base.
He carefully merged his own DNA, even slipped in fragments of his soul, to make eventual possession easier, seeding these new bodies for the future.
To stabilize them, he introduced Hashirama's cells, fusing Senju vitality into the mix.
He added the enzymes and genetic traits from the Sage Transformation clan, hoping for a vessel that could wield senjutsu more naturally, with no side effects, no risk of rejection or madness.
And it was working. Only one clone was truly viable, a boy with shock-gray hair, skin like fine porcelain, and new eyes: golden Sharingan, half-tomoe, half-mangekyo, a flooded pattern never seen before.
The eye color and the aura were something unique, even beautiful, a side effect of the combined genes and the senjutsu enzymes.
Orochimaru did not implant these eyes in himself, not yet; he wanted to see what they would become as the body matured.
He flooded the clone's incubation tank with some yang chakra, as Ryusei's notes taught him, special serums, and slow doses of the White Snake Sage's own venom, a gift after months of negotiation and demonstrations of respect.
The White Snake Sage had finally taught him the real laws of senjutsu: only some lucky animals, initially the ones from the three Sage Regions, led by their Great Sages, like her, or humans bonded closely to them, could ever learn the Sage Mode for some reason, as humans were "too far away from nature".
However, it varied; some humans could only reach Sage Mode imperfectly, while a rare few could achieve true, complete mastery.
Jiraiya, for example, never managed more than an incomplete form.
But this vessel, raised in senjutsu energy from day one, bred for transformation, would make snake-like power as natural as breathing.
As Orochimaru monitored the clone, he felt a mix of pride and anticipation he hadn't known in years. This was the work of his lifetime.
Shin's genetics allowed for the Sharingan to fuse in ways Uchiha probably never imagined.
The pattern that emerged was dazzling, golden, pulsing with strange chakra and showing both the hypnotic tomoe and the dangerous swirl of mangekyo.
He suspected it would be very powerful, with all the powers of the original Sharingan, plus whatever new techniques the unique hybridization allowed.
He'd even started to wonder: would this vessel awaken wood release, thanks to the Senju cells? It seemed possible, to an extent, of course.
And the Sage Mode wouldn't just be ordinary.
Born for it, the body would absorb and balance natural energy flawlessly, so almost no preparation time necessary, no risk of petrification, no threat of madness, just pure power.
Physical strength, speed, reflexes, durability, enhanced sensory perception, using natural energy as a medium to an extent, vast chakra reserves, and rapid regeneration would all come naturally, along with the complete arsenal of senjutsu techniques, eventually too.
His control would be so fine-tuned that new jutsu and chakra modes might emerge naturally, abilities unique to a body like this.
This new Sage Mode wouldn't just imitate the Snake Sages of Ryūchi Cave.
It would be something entirely different, a unique, more evolved form: 'Dragon Sage Mode.'
It would surpass the ordinary limits of snakes and tap into a higher tier of power altogether.
He took precautions, of course.
That was why Orochimaru had spent the last few months almost obsessively monitoring and protecting the small, gray-haired vessel in the tank. He knew how rare this opportunity was.
The clone also couldn't be rushed to adulthood; the process slowed as it grew more complex, and at best, it would reach Ryusei's age soon, the edge of puberty, before natural growth had to take over.
Orochimaru calculated, weighing risk and reward.
Even at that age, the vessel would already surpass his current body.
Once he moved his soul over there soon, he could guide the growth personally, shaping it with every year.
He thought back to his first attempt at Sage Mode, deep in Ryūchi Cave.
He'd survived only by caution, never blindly accepting the White Snake Sage's venom, never letting ambition outrun preparation.
Now he saw the wisdom in that.
This time, he would have a vessel bred for power, not one twisted by last-minute adaptation.
True Sage Mode required more than just chakra control or a strong body.
You needed both in perfect balance, your physical and spiritual energies, and your natural energy in harmony, each amplifying the other.
Most failed because they underestimated this balance.
Orochimaru had always known his original body was too frail, but now, with this vessel, he'd finally have the perfect foundation for both power and control.
He remembered how easily others had died in the cave, petrified by their own ambition.
He was careful, patient, never foolish enough to take the White Snake Sage's venom without preparation.
That patience was about to pay off. This time, he'd built the vessel himself, fit for the load, molded for the future.
He glanced at the tank often, gray-haired, golden-eyed face suspended in fluid.
He felt it, something close to reverence.
This was no ordinary experiment. This was ascension.
Soon, he would abandon his current shell and transfer into this vessel: the culmination of every technique, every bloodline, every ambition.
A new "hardware" for a new level of jutsu, chakra, and physical potential.
His soul would finally settle into a body worthy of all he'd stolen, all he'd learned.
And he would not lose himself to madness or decay. Not this time.
With the fusion of Senju, Uchiha, and Sage blood, with the new golden Sharingan and perfected control over natural energy and senjutsu, he would become something the shinobi world had never seen.
A true sage and higher being, not by luck or birth, but by design.
Its power, too, would only deepen and evolve as the vessel matured, growing more naturally potent with every passing year.
He had also refined his most advanced soul transmigration technique to the point where he could selectively carry over only the 'best' parts of his current physical self through the transfer, like his vast and high-level jutsu procedural skills, muscle memories, specialized chakra pathways, and key neural adaptations, while leaving behind any lingering weaknesses or the general mediocrity of his old body, along with the usual baseline of memory and personality that the soul always carried.
In this way, he would fully inherit the strengths and latent power of the new vessel, merging its superior potential with his own hard-earned experience to become something far greater than either could ever be alone.
Orochimaru smiled faintly in the dim green light of his laboratory, the soft bubbling from the tank the only sound in the room.
The world would not see what was coming until it was already too late.
He was on the brink of something greater, and for the first time in decades, he was thrilled.
He often found himself lingering by the tank like this, studying the developing vessel through the glass, almost lovingly, as if watching over his own child.
This creation wasn't just another experiment; it was his masterpiece, the next step in his evolution, and the one thing in all his decades of research that truly filled him with pride.