A somewhat run-down house—this was Kurogane Ren's residence.
In theory, being a ninja wasn't a low-paying profession. Even the simplest missions offered decent rewards.
As a Special Jonin, Kurogane Ren shouldn't have been unable to afford a more comfortable home. Even if not luxurious, it certainly shouldn't have been this shabby.
And that was indeed the case. It was simply that Kurogane Ren had very low requirements for where he lived. As long as it served basic residential functions, it was enough.
Inside, everything one would expect was present, but the overall atmosphere felt crude and lifeless, as if the owner rarely stayed here.
That was also true. Most of the time, when there was no war, Kurogane Ren was out on missions beyond Konoha. Naturally, he seldom returned home.
Even when he did, he would remain in a single room, studying sealing techniques. There was little trace of everyday life.
Walking to his desk, Kurogane Ren sat down and tapped his fingers lightly against its surface, calmly considering his next move.
Stealing the Demon Assimilation Technique was something he had to do. It was his only chance to overturn his fate with this painfully average body.
But what came after stealing it?
He would need to master it in an extremely short time. At the very least, he had to complete a fusion before Rin Nohara was captured by the Mist ninja, solving his greatest flaw—his lack of chakra.
The question was how complete the technique currently was. It likely hadn't reached the stage of fusing five bodies, but fusing one or two should already be possible. Maybe even three.
The early stages of developing a technique were always the most difficult. Even if later stages weren't perfected, Kurogane Ren was confident he could fill in the gaps himself.
As for the bodies needed for fusion? He had already prepared them. His twenty-seven years hadn't been wasted.
Where were they kept? Certainly not within Konoha. Unlike Hiruko, he wouldn't place his experimental base inside the village and wait to be discovered.
With that in mind, Kurogane Ren picked up a sealing scroll from his desk and began reviewing it from the beginning, considering possible modifications.
That night.
Setting the scroll aside, he looked toward Hiruko's experimental base, which still showed no signs of activity. Even Kakashi's side remained completely quiet. A trace of anxiety crept into his heart.
Had he remembered incorrectly? The original story was vague about this part. As soon as Hiruko learned about Kakashi obtaining the Sharingan, he had already been discovered and driven out by the Sannin.
"That shouldn't be the case…"
Kurogane Ren frowned. Could it be that Hiruko branded Kakashi with the puppet curse after being expelled?
When Hiruko placed the puppet curse on Kakashi Hatake, Kakashi clearly still had a two-tomoe Sharingan. That meant it happened after the Kannabi Bridge battle but before Rin was captured.
"Could it be that after being expelled, Hiruko returned to Konoha…"
Kurogane Ren frowned deeper, considering the possibility. Then he recalled how Itachi Uchiha had once entered Konoha openly with Kisame. Instantly, a sense of dread crept over him.
Thinking about it, with Konoha's tendency to keep barrier passwords unchanged, it wasn't impossible.
Fortunately, although he hadn't seen Hiruko leave, he also hadn't spotted the Sannin. That meant his plan hadn't failed yet.
If things really unfolded as he feared, then he would have to adjust his plan.
Hiruko managing to escape from the Sannin likely meant they had shown mercy due to their past relationship. Still, appearances had to be maintained, so Hiruko would definitely be injured—though the severity was uncertain.
Regardless, this was his only chance to act. Once Hiruko went into hiding to collect bloodline corpses, finding him again would be nearly impossible.
Truthfully, Kurogane Ren didn't want to confront Hiruko. Not for any moral reason, but because even without using the Demon Assimilation Technique, Hiruko's strength was at least at the Jonin level—only inferior to the Sannin.
The fact that he could easily place a puppet curse on Kakashi proved his strength. Even if Kakashi's Jonin rank was due to wartime promotion, he was still no weakling. Facing someone like Hiruko with only Special Jonin strength was far from safe.
If he could intercept Hiruko, that wouldn't be the worst outcome. The worst outcome would be losing the chance entirely and being forced to develop everything himself.
He had considered researching it on his own before, but there were two problems. First, he might not succeed. Second, he already had other techniques to focus on. With his experimental base outside Konoha and no assistants, he couldn't afford to spread himself too thin.
Since the Demon Assimilation Technique already existed in the original story, it made far more sense to take it and devote his efforts to other techniques.
Taking a deep breath, Kurogane Ren tapped his forehead and slowly calmed himself.
Wait a little longer. The Sannin hadn't appeared yet. Things hadn't reached the worst-case scenario. There was still hope.
And so, with unease gnawing at him, Kurogane Ren waited until the third night.
When he finally opened his bloodshot eyes, they were filled with joy.
Because Hiruko had finally left his experimental base—and was heading straight toward Kakashi's location.
Letting out a breath of relief, Kurogane Ren stood up and began moving. Even now, he couldn't afford to be careless. Getting spotted by patrolling ninja would draw unwanted attention, something he absolutely wanted to avoid.
Soon, he arrived at the entrance of Hiruko's experimental base. Following the exact method he had observed before, he moved inside step by step without error.
Once inside, it was beyond the reach of his crows' surveillance. He had always kept them at a distance to avoid detection.
But that didn't mean he had no alternatives.
"Water Release—Reconstruction Technique!"
Forming hand seals, Kurogane Ren activated his chakra.
Yes, Water Release. His chakra nature was water and earth—utterly ordinary, nothing like the protagonist's wind or lightning.
Water wasn't bad, especially in Konoha, where the Second Hokage had been a master of it. But earth release was troublesome. The most useful techniques, like Light-Weight Rock Technique and Heavy-Weight Rock Technique, were exclusive to the Stone ninja.
As for combining earth and water to create Wood Release? Impossible. Even Mei Terumi only had Lava Release from those elements. Wood Release clearly had something unique—likely tied to the First Hokage's lineage.
Still, Kurogane Ren didn't care much. Once he had the Demon Assimilation Technique, acquiring other abilities would only be a matter of time.
During this period, he had developed several techniques, including the Clairvoyance Technique.
And now, this Water Release—Reconstruction Technique…
A thin layer of liquid spread from beneath his feet, flowing rapidly across the ground ahead. Within it, footprints began to emerge—some entering, some leaving.
Kurogane Ren focused on the clearest set—the fresh tracks left by Hiruko.
Stepping precisely into those footprints, he advanced deeper into the base.
Soon, the space opened up. What greeted him was a horrifying sight—countless corpses. Some lay exposed, while others floated in tanks filled with solution.
The air reeked of decay. Kurogane Ren frowned.
Hiruko was far too careless. His own experimental base was much cleaner—and very different.
Hiruko's subjects were mostly animals. His own… were primarily the bodies of targets he had eliminated during missions.
But now wasn't the time to dwell on that.
At this point, it was relatively safe. Traps would usually be set in the corridors, not in the laboratory itself.
In fact, he hadn't encountered any traps on his way in. Unlike his own base, which was filled with deadly mechanisms—poisons, acids, and more.
Thinking about it, in the original story, the Sannin had entered Hiruko's base without resistance and only encountered him inside. That suggested there were likely no traps at all—or at least no alarm systems.
If it had been his base, even the slightest disturbance would alert him immediately.
But now wasn't the time to criticize Hiruko.
His eyes scanned the room quickly until they landed on a large stack of experimental records.
Kurogane Ren felt a headache coming on. He would have to sort through all of this later to find what he needed.
Letting out a sigh, he got to work.
Taking out a prepared scroll, he released its seal, revealing a large number of blank scrolls.
Then he opened Hiruko's research notes. There was no time to read them here, but he had already prepared for this.
"Water Release—Replication Technique."
Clear water spread across the records, clinging to every character. Then, as Kurogane Ren brought out a fresh scroll, the water seemed to find a new target, flowing into it.
Moments later, countless words began to appear on the new scroll—perfectly replicating Hiruko's handwriting.
A satisfied smile appeared on Kurogane Ren's face as he quickly copied each record.
By the time he finished the last one, he could barely suppress the urge to laugh out loud.
But this wasn't the place.
Forcing himself to calm down, he carefully inspected every corner of the lab, even Hiruko's bedroom, ensuring nothing was missed.
Only then did he stretch.
Forming hand seals again, he activated the Clairvoyance Technique once more—and saw that Hiruko had already succeeded in his objective and was on his way back.
Kurogane Ren wasn't worried about running into him. Entering had been troublesome, but leaving would be much easier.
He had already restored everything to its original state. The footprints overlapped perfectly with Hiruko's. The only difference was a slight increase in humidity from his Water Release techniques.
But such a minor change would be difficult to notice, especially for someone like Hiruko, who didn't pay much attention to details—and who was likely elated after his success.
Kurogane Ren had no interest in leaving clues behind for amusement.
While others might enjoy the thrill of escaping at the last second, he had already synchronized with his summon.
Inside his shabby home, a crow used its small body to slowly unroll a massive scroll inscribed with a technique.
"Summoning Technique!"