Once he was finally nested in place and sure Kanae had baited the pursuers away after a while without trouble, without them even suspecting anything, Ryusei allowed himself to relax his presence a little.
Only then did he start forcing the Yang Palm through his body again, trying to suppress the injuries all over him.
Long-term damage potentially stemming from that didn't matter; he couldn't afford to care about that now, not with this many obstacles still ahead.
Then he struck again at the old soul. Another fierce, devouring surge, hammering into the original owner's will.
The boy's spirit still clung on, indignant, unwilling to yield, fighting tooth and nail to keep the body.
"I'm sorry, man," the new Ryusei thought coldly. "Even if your identity will leave me with insane problems and dangers for years, even if I somehow survive today, it's still better than rotting in that ghostly void. I'm not going back to being just a soul. Not again. I finally got my chance to live, and I'm not letting go."
There was no pity in him for the soul he'd stolen from.
"Besides, danger is just opportunity wearing a knife. Your hidden Senju bloodline… I can work with that. I can make it my weapon. If I play it right, I can rise in this world to real power, real status, and make something extraordinary out of this life. I feel like I don't even need any stupid 'system' with this identity, after all, that would also make it too boring and stupid for me... Imagine how weird it is, actually, constantly living with such a thing of unknown origin."
His mind wandered for a breath. "Actually, this is way better than, for example, ending up a slave in a xianxia backwater. Those people still rise against the odds, get their three-year challenges, and slap everyone who doubted them. Why can't I do the same, but with a far better starting point? Not to mention… this world was already one of my favorites back when I was alive on Earth. I knew it inside out. I liked it more than most fantasy worlds out there."
The man who now called himself Ryusei had once been a terminally ill patient, an orphan with nothing, trapped in a body that was failing him, wasting away while hating the pharmaceutical vultures, the smug doctors, and everyone else living the life he never could, coping mostly with consuming various fantasy mediums.
He'd actually spent years daydreaming about such legendary "transmigration".
But when the disease finally took him and he actually arrived here, he'd learned the truth.
Walking as a soul through someone else's mindscape, on the constant edge, trying not to be noticed... living in endless, gnawing boredom, for who knows how long, had burned the fantasy right out of him.
He had grown to hate transmigration and the universe that had dropped him here.
Only now did that hatred twist into something else.
This was his first real chance to climb in any world and reach the top - albeit only if he survived today first and then many such 'todays' probably later.
After about fifteen minutes, Ryusei's eyes opened again.
His breathing steadied, and the deep frown on his face eased, only slightly, but enough to be noticed.
The news was good, in a way, but not completely.
He had finally broken the other soul's cohesion. The old Ryusei no longer had a clear sense of "self."
But the job wasn't done. Far from it.
Most of that soul still floated around him inside the mindscape, trapped in a kind of limbo. He had only devoured a small portion, just enough to weaken it and extinguish its unity.
The rest he kept circling his own soul like meat in a slow grinder, chewing bit by bit.
There was a reason for this caution. He couldn't simply tear it all apart in one go.
Fundamentally, the more he devoured without waste, the stronger his new spiritual energy would later be, but not only that.
If he did, he risked losing more than just a rival consciousness; he could lose chunks of memory that were vital for his further survival in this world.
There were still countless details of old Ryusei's life he hadn't seen, for example, complete clues about his identity, potential enemies, and maybe even possible escape routes.
Up until now, he had only stolen fragments, scattered moments glimpsed when the boy slept. In truth, he had maybe ten, twenty percent of those twelve years in his head.
Then there were the procedural skills. Techniques, reflexes, jutsu execution, muscle memory, things that couldn't be relearned overnight.
Losing that would cripple him completely. In that case, he might as well slit his own throat.
At the same time, he couldn't allow the original self to remain in any form that could resist him later.
He wasn't going to share this body. He wasn't going to let its duller instincts or what he saw as a lower intelligence muddy his own.
The fusion had to be exact. The memories and skills would remain as an addition to his own ones from his past life, but the will, the personality, and the decision-making would remain.
All of it would belong to him alone.
The Earth-born mind would sit on the throne, and the Senju's past would be nothing more than a well-stocked armory for him to use.
Additionally, since the essence and form of the previous Ryusei were now completely erased, he decided to keep the name for himself in this world.
As for fulfilling the teenager's old dreams out of gratitude… he wasn't the type to fool himself like that.
He had taken the boy's body by force, destroyed his soul - what meaning could goodwill have in a situation like that?
What mattered now was fully absorbing every last shred of the boy's memories, breaking them down with a cold, neutral eye, and deciding which parts were worth using. Sentiment wouldn't guide him - but utility would.
Still, strange small undercurrents were pulsing up from deep inside, emotions that weren't his own, just from this small of a fusion so far.
A quiet malice toward Konoha… and toward the Third Hokage and his faction, who, according to the boy's memories, had played the largest role in the deaths of his parents, almost certainly.
There was also that instinctive pull toward the Senju name, a tribal loyalty that had been etched into the boy's heart as perhaps some kind of solace without anyone to rely on.
He knew these feelings might only grow stronger as the fusion of souls and memories reached completion in a few weeks, according to his estimation, in the future.
But even if they did, they would be forced to take second place to his true priorities: survival first, then power, climbing as high as possible in this world's food chain.
Ryusei decided it was time to move. It would be bad if something suddenly went wrong with the depot he was supposed to secure and destroy.
Even while they are clearly winning their battles over time, and could go there once they are done instead, many unforeseen factors could arrive regarding that location by that point.
Better to complete his own task now and leave no gaps for anyone to use against him later.
First, he ran a quick assessment of what strength he could still pull from the body - his inherited procedural memory, the current state of his injuries, and the chakra reserves left.
The original owner had mastered two B-rank offensive jutsu tied to his only two nature affinities, but at this point, those were completely out of reach.
Still, he remembered enough about them to know why they worked so well together. One pierced an enemy from multiple angles at once. The other split the battlefield and trapped targets in place.
Both were only refined and improved versions of pre-existing elemental ninjutsu, which was nothing unusual in the shinobi world.
Every technique was just another step in a long chain of evolution - no one tried to reinvent the wheel from scratch.
And Ryusei's predecessor had a rare advantage. He still had access to a private, deep Senju archive of elemental jutsu, untouched when Tobirama dissolved the clan.
That was thanks to his bloodline: one of the most powerful within the Senju, second only to the patriarch's line.
His family had been a branch of high standing, consisting of the last Senju Grand Elder, for example.
His father had even led the Senju revivalist faction during the Second Great War at some point before he was dealt with.
That status came with personal collections of scrolls and knowledge that Tobirama and his loyalists hadn't been able to confiscate as "public Senju heritage" when the clan officially disbanded.
With that stockpile, the original Ryusei had been able to adapt and create techniques tailored to his talents.
And then there was his mother. Once one of the top medical-nin in Konoha, she'd held a senior position in the village hospital.
Her notes had been the key to his developing his unique Yang Palm technique. The widely known Mystical Palm had only provided a basic conceptual framework - the real details had come from her work.
However, none of the three options was usable anymore. The Yang Palm was out because his body was already fully patched up; there was nothing left it could fix without risking damage from overuse.
Additionally, for example, his Senju-style "strong fist" traditional taijutsu was also unusable. With his current limits, taijutsu was even harder than ninjutsu.
For ninjutsu, you only needed to form the correct hand seals together with the use of the correct brain visualizations, and calculate the chakra flow once to execute the technique.
But taijutsu required constant, rapid adaptation in real time, countering countless unpredictable inputs.
That level of reactive precision depended heavily on deep procedural memory, which he now only possessed in the smallest fragments, having more in the so-called 'general memory' category.
"So what's left? How do I take down those three…?"
His mind slowly churned over the remaining options.
"Yes… there's that… and that…"
He began piecing together a plan, one that might work if he executed it perfectly. If not, he was finished.
Failing to complete his part of the mission probably wouldn't bring harsh punishment - at least on the surface.
It would be obvious the failure wasn't stemming from either personal disobedience or incompetence, but from unforeseen factors - a strong "enemy" asset the village intelligence hadn't reported to him at all concerning this mission.
But that didn't mean he was safe.
In Konoha's shinobi culture, and judging from some examles he'd seen in the original Ryusei's memories, while he wouldn't be punished at all, such a failure could easily still be twisted into a reason to send the team on another B-rank mission far too soon, before he recovered and adjusted, especially if the higher happen to be biased, like they were against him now.
Ultimately, the Hokage had the final say regarding nearly everything in the village, and technically, he was just another tool of his.
Common sense and "fairness" only came into play when the situation reached a point where ignoring them would damage the Hokage's reputation too much to risk.
At that point, he'd weigh the bigger picture and avoid being openly unreasonable, but only for that reason, not out of any genuine sense of justice.
And in this case, no such threshold had been reached.
There'd be no problem for him to say, "It's not punishment, just a chance to make up for the last mission," while knowing full well it could finish the job the previous assassin failed to do.
If that next mission turned into another assassination attempt, which was more than likely, it could be worse than this one from the very start.
They would have the chance to recalibrate, adjust their approach, and send an even greater threat.
Worse still, it would happen before he had recovered from today's injuries or the strain of the soul fusion, and before he had surpassed the original owner's strength as he thought he would if given a bit of time.
He could still be operating at a fraction of it. That made his next move all the more critical.