Within the week, Ryusei had done it.
He put both brothers through every manner of mental and physical torment, yet still the Mangekyō refused to awaken.
Their three tomoe had sharpened, though, looked heavier, darker, and carried a depth that ordinary Sharingan did not.
The potential was there, but locked, like the eye itself was hovering at the edge of evolution, but incapable of crossing it due to innate limitations, perhaps.
Ryusei exhaled through his nose, half-amused, half-disappointed.
"This is as far as I can take it."
It would be enough.
This quality alone was unmatched by anything short of the Mangekyō itself, and that made it worth handing over.
Whatever Orochimaru wrung from them afterward, whether breakthrough or failure, was his concern.
His only task was to make sure it held equal value for the price he intended to demand.
Ryusei, after finally ending the brothers and putting them out of their misery, sealed their eyes into a scroll he had crafted over the past week, layered with precise Yang Release bindings meant to preserve and nourish them.
Katsuyu couldn't be used this time; if she carried them, Tsunade would inevitably learn of it, and this was something he intended to keep hidden this time.
He'd experimented in the meantime, testing Yin Release streams on the eyes externally to see if they could be pushed further, but nothing changed.
Perhaps the answer lay in cellular work, the kind of science only Orochimaru truly thrived in currently. Ryusei left it there.
His grin returned. He had no fear of arming Orochimaru with another Mangekyō, should it bloom under his care.
His own path was grander, steeper, and he was confident enough in his strength to stake it.
As for cheating the eyes into evolution with genjutsu, that was a fool's dream.
If it were possible, the Uchiha would have long ago lined themselves up, casting advanced mass illusions of grief and slaughter until every last one bore Mangekyō, and they would have ruled the world by now.
Trauma was the price. Always real, always personal. There was no shortcut here.
Afterward, Ryusei summoned a medium-sized fragment of Katsuyu that had been storing the stolen beast chakra and began to toy with it again.
For the past two weeks, he had been experimenting with it in secret, inspecting, molding, refining.
Thanks to his sensory mastery, he found he could observe and shape raw chakra more finely than even many Hyūga could, and with the Byakugan added into the mix, the synergy was frightening.
Slowly, through trial and error, he forced the wild energy into something usable.
This time, he drew some of it into his arm.
A faint greenish frost gathered, then hardened into jagged shards of ice that glittered with an unnatural sheen.
Not pure Ice Release, there was something else within it, a subtle acidic sting and the faint roughness of coral textures. Ryusei smirked.
So it was true, when imbued with beast chakra, certain releases surfaced as if they were second nature, requiring barely a flicker of hand seals.
His grin sharpened further.
With these reserves, before he consumed them all, his strength had already pushed past the Mid-Kage threshold.
He was standing more and more among the small handful of proper Kage-level shinobi in the world, no more than ten or twenty in the world.
Yet Ryusei knew better than to be drunk on shortcuts.
From Quasi-Kage to now, he had climbed by leaning on borrowed power, Tsunade's contracts, her chakra, and now the stolen beast chakra.
From this point forward, he would inevitably have to return to that slower climb, steadier, through the long grind of his own training.
Also, the higher the summit, the harder the next step, and the more merciless the cost of failure. So he didn't grow too drunk on current results.
During those two weeks, Ryusei also poured effort into perfecting his unique Killing Intent technique.
It was proving itself as one of his most efficient weapons, the lowest-cost way to put down chūnin and even jōnin without bleeding himself dry of chakra now that he was stepping deeper into Kage territory.
A single pulse could freeze them in place for just a heartbeat, and that was all his speed and taijutsu needed to finish the job.
Like a raw aura of domination, it pressed directly onto the spirit. In many ways, it resembled the "Haki" he remembered from his old world.
It was the closest he had to true genjutsu, only this was built on his sensory mastery and Yin Release.
What made it deadlier was its flexibility.
He could shape it wide and unfocused, crushing squads of lesser shinobi into paralysis or unconsciousness, or sharpen it like a blade, drilling directly into the mind of an elite.
He had already tested the latter against Shirou, dropping him in silence before the man even realized death was upon him.
But this wasn't the only frontier for his Yin Release.
While Reiji and Shirou were still alive, bound and sealed like specimens, Ryusei experimented with something else, too.
He attempted to send his own soul presence outward, weaving Yin Release into the process, to peel information from theirs.
At first, it was crude, fragmentary impressions, flickers of memory, but with each attempt, he refined it further.
The idea was simple in theory, impossibly difficult in practice.
He needed a method that would allow him to uncover hidden truths from the depths of another's mind, something undeniable.
If he could elevate the technique to that advanced level, then Tsunade's soul could also somehow stand beside him and witness it directly.
Then, with her own eyes, she would see what really happened to Nawaki.
The work was grueling, but his foundations carried him.
His unusually strong spiritual energy, his knowledge of souls, his sensory perception, and Orochimaru's scattered notes combined into a framework.
With it, Ryusei felt the borders of possibility shifting. He was close.
Already, in controlled conditions, he could pry surface information out of others in certain situations, snatches of thought, flashes of images.
Actually, what led him to develop that ability so much was almost absurdly fortunate.
Ever since the Grass Country incident, when that Root Yamanaka, with his soul beams, attempted to assassinate, but was dealt with by him instead, Ryusei had preserved the man's body in a strange semi-living state.
He hadn't known exactly why at the time, only that his instincts told him the man carried too much dirt on Danzo inside his mind to discard right away blindly.
If he ever mastered a soul-reading technique, he wanted that filth for himself.
After experimenting on the Uchiha brothers, he'd managed to push the concept to initial success.
Reading memories directly to an extent.
The moment he tried it on the sealed Yamanaka corpse, the result shook him.
The man's name was Junsaku Yamanaka. A quiet, obedient tool of Danzo, who had carried out more than his share of black operations.
And buried among those memories… Ryusei found hints of Nawaki's death.
Ryusei had always scoffed at the official story. Hashirama's grandson, dying like some fresh academy dropout by stepping on a random explosive mine? It had never sat right with him.
Now the truth felt clearer. Junsaku's specialty wasn't direct assassination, but sowing confusion, manipulating thoughts, twisting timing until a shinobi made the wrong move at the worst possible second.
With that ability, causing Nawaki to stumble into a trap wasn't just possible, it was almost too neat.
Ryusei exhaled slowly, slit eyes narrowing. "So that's it… the same man who killed the original owner and almost killed me, killed Nawaki first."
The irony wasn't lost on him. The circle closed, the strings tied.
Junsaku wasn't just some faceless Root operative.
He was a ghost that had haunted the Senju line for years.
And if he had ended Nawaki, who knew how many other Senju deaths were stamped with his shadow?
The ability was perfect for Danzo's methods, death by borrowed hands, accidents that no one could trace back.
Ryusei was glad he had trusted his intuition, glad he had kept that body when most would have burned it.
Now all he needed was refinement, a technique advanced enough to draw out every shred of proof from the man's soul.
When the time came, he would present it to Tsunade directly.
And that wasn't the only plan he was plotting.
Once he returned to trade with Orochimaru, he would secure something else. Insurance.
Hashirama's cells for Kiyomi.
He had already accepted her as his little girlfriend, his to raise and protect.
He wouldn't let her eyes burn out when she awakened the Mangekyo.
Of course, it could only be done after a long time of research and in a safe way.
And Ryusei was certain she would awaken it.
Unlike those pathetic brothers, she had the right potential.
He had already thought of ways.
Perhaps one day, he would stage something, her belief he was gone, rip open her heart with loss.
Or, if his soul technique advanced far enough, maybe he could force it more directly, inserting himself into her soul, shaking her from the inside until the Mangekyo bled into existence.
Either way, Ryusei was patient.
Ryusei was also honing something far more dangerous than his usual training.
He had begun shaping that jutsu-shiki that let his soul pierce into the Pure Land itself, not just to glimpse it, but to seize fragments of chakra memory left behind by shinobi who once mastered fused elemental releases.
If he could carry those imprints back, he could refine them into molds for himself, shortening the path toward his own advanced releases.
This was why he wanted Edo Tensei from Orochimaru.
He already knew the potential existed in him; his transmigration had left him with the seeds.
What he lacked were the perfected molds. With this method, those molds were within reach.
After wrapping up those experiments, Ryusei didn't want to waste any more time.
The single Byakugan he had implanted was already serving its purpose for training, but it wasn't enough.
For the kind of research he envisioned, he needed a pure, proper specimen from the Main Branch.
Something worth dissecting, worth building from.
Now was as good an opportunity as any.
He formed a seal, and a clone flickered into existence.
Its orders were clear: head southwest, toward the Land of Rivers, where Konoha's lines tangled with Suna's.
If there was anywhere to catch a Main Branch pair stretched thin, it was there.
The clone gave a small nod, already suppressing its chakra until it blurred against the air.
Then it slipped into the trees, vanishing from sight.
Ryusei leaned back after watching it go, his narrow eyes gleaming.
"It's only a matter of time. Let's see how hard it really is to pluck one of you from the nest."