This place was a bloody mill fueled by ninja as "raw materials," operated with the most primitive production techniques.
From the casual descriptions of the ninja named Tushi, Yujin could already get a general idea of his so-called "research level."
Transplanting a ninja's heart into a beast was meant to grant the creature—one with decent physical attributes—the ability to produce chakra.
Replacing the beast's brain with that of a ninja's was because the human brain had higher intelligence and could more easily understand commands.
It was easy to imagine that such a brain would be under the influence of genjutsu or some form of curse seal.
Looking at this kind of research approach—"take this out, shove it in there"—it was crude and brutal, to say the least. Based on this, Yujin could guess that most of Tushi's "products" were slapdash and of questionable quality, with very limited lifespan.
As for Tushi's combat methods—or more accurately, his ability to subdue other ninjas—they were actually quite formidable.
On one hand, he used genjutsu to deprive opponents of their senses; on the other, he employed special techniques to strip them of their chakra. The combination didn't make him "invincible," but it was enough to neutralize most ninjas who lacked intel advantages.
Unfortunately for him, he ran into Yujin.
After knocking Tushi unconscious, Yujin waited until both the people and beasts in the underground chamber were nearly drowned, then finally "opened the floodgates."
He formed hand seals and once again used the Water Style technique: Water Formation Wall.
Water swirled around Yujin, slowly at first, then rapidly gaining speed. In an instant, a ring-shaped column of water resembling a "water tornado" spun upward around him, simultaneously clearing the surrounding floodwaters and spiraling skyward.
The water shaped itself like insect eggs awakening underground in spring, gradually breaking through the layer of withered leaves and branches above.
Under Yujin's control, the water easily peeled away the coating overhead. After destroying the structures above, the spiraling torrent surged all the way to the surface.
Water levels in the underground chamber dropped rapidly, and a huge volume of water was released into the nearby town.
It wasn't that Yujin harbored a destructive impulse toward civilian life; this was merely a warning. Any sensible person in that town, upon witnessing this Water Style technique, would know to evacuate immediately.
No one wanted to be caught in a battlefield between ninjas.
How many people in that town were smart? The answer: when lives were at stake, everyone suddenly became smart.
Heavy breathing and violent coughing echoed through the underground chamber—they had narrowly escaped death.
Dragging Tushi, whose body was still half-submerged, Yujin began walking while surveying the imprisoned people in the cells.
Since the caster had lost consciousness, the genjutsu controlling the prisoners had also dissipated. Drenched in cold water, they quickly regained awareness.
There were about thirty ninjas imprisoned here, so Yujin's search was swift. After checking only a few cells, he spotted a familiar face.
It was exactly the person he was looking for: Chihori of the Hanemiya Clan.
Fortunately, Yujin had found his clanswoman. Unfortunately, she seemed to be the only one.
Perhaps she was the only one who'd been "trafficked," or maybe the others had already been sacrificed in those cruel experiments.
Chihori was a kunoichi around seventeen or eighteen years old. Her face was deathly pale, and her gaze vacant.
Yujin stood in front of her cell. Noticing something blocking the dim light, Chihori instinctively looked up.
Only when she recognized Yujin's face did a trace of life return to her eyes.
She opened her mouth to speak, but Yujin gently shook his head to stop her.
There were still many survivors here, and out of instinctive caution, he didn't want to reveal the true purpose of his appearance.
Better to make it seem like he had come to save everyone, not just a specific individual.
To be honest, according to typical ninja doctrine, after rescuing the primary target, the rest should be silenced.
After all, they held no value, posed no threat, and were likely to turn hostile if left alive… In short, they were better off dead.
But Yujin didn't want to do that.
It wasn't that he was kindhearted, or had some hypocritical saint complex. He simply didn't want to.
To him, these ninjas had no value. Whether they lived or died was irrelevant.
The only reason he chose not to kill them was because Yujin had a bit of a "mental cleanliness" issue.
Compared to the man he was dragging along, he just didn't want to become someone like him. That's all.
There were many paths to walk in times of chaos. In this age where if I don't kill, others will kill me, Yujin wasn't opposed to becoming a cold-blooded killer—but he refused to become inhuman.
So this little bit of mental cleanliness upheld some of Yujin's baseline principles as a human being.
If anyone knew what he was thinking, they'd likely scoff and ask:
"What makes you think you're different from the rest of us?"
In any case, because Yujin didn't intend to kill everyone here, he had to go about his rescue with a bit more tact.
Yujin retrieved a set of keys from Tushi and unlocked Chihori's cell. After removing her shackles, he gestured with his eyes for her to leave quickly and said:
"You're all free now."
Chihori understood and immediately fled as fast as she could.
Only then did Yujin begin unlocking the others.
Once freed, the prisoners glanced at Yujin fearfully, then quickly scurried away from him as if avoiding the plague, scrambling through the cell doors and fleeing the chamber.
Yujin didn't blame them. He wasn't naïve enough to expect them to say "thank you" for being rescued.
By freeing everyone, his act of saving Chihori wouldn't stand out—and no one would suspect his true motive for being here.
After everyone from that cell block escaped, Yujin moved to the next.
Suddenly, one of the imprisoned ninjas began shouting hysterically:
"Haha! I knew it! My clan would never abandon me—they must've sent someone to rescue me!"
Not only Yujin, but even the other dazed prisoners turned to look.
The unconscious Tushi was awakened by the noise. His face twisted in fury the moment he came to.
Even though his neck had been practically broken, the guy was still alive and conscious—able to fight back.
Yujin looked toward Tushi, curious to see what he would do.
Tushi's hands clapped together as he rapidly formed hand seals.
In the next moment, a dozen earthen spikes shot out of the stone walls—sharp and deadly like lances—impaling the shouting ninja through the chest.
Yujin: "…"
He hadn't expected that.
"I knew it… I should never have targeted someone from a major ninja clan," Tushi muttered bitterly.
"You sure talk a lot… For someone so desperate to stay alive."
A good question. The only problem was—it didn't sound like a human being talking.
Technically, Yujin should have interrogated Tushi—asked if he was acting alone, if there was a criminal organization behind him, or if there was a mastermind pulling strings. But none of those answers mattered to his goal here, so he didn't care.
He didn't ask, and Tushi didn't answer.
Yujin simply broke his arms.
The moment Tushi regained consciousness, Yujin had been on high alert—ready to counter any surprise attack. He just hadn't expected the target of the ambush to be someone else.
While Yujin had destroyed Tushi's "research," the latter's deepest hatred wasn't for Yujin—but for the person who brought Yujin here.
In Tushi's eyes, Yujin was just a hired blade. The true culprit—the one who ensured his downfall—was whoever sent Yujin after him.
Now that someone had foolishly proclaimed themselves the summoner, Tushi naturally took revenge on them first.
Yujin looked at the man who had been moments from salvation but rushed to his own doom and thought:
Some people in this world simply can't be saved.
A member of a major ninja clan? Probably just used to arrogance.
Yujin glanced at the dead man's forehead protector. The emblem showed three semicircular arcs cradling a sphere. He didn't recognize which clan that belonged to.
The man was dead, but he'd given Yujin a perfect excuse to distance himself.
"Major clan? What's that worth compared to me—Uchiha Izuna? I didn't come here for anyone. I just couldn't stand what you were doing—so I destroyed it all."
Indeed, when walking the ninja world, one must never change name or surname lightly.