As Shinji activated his dojutsu, Kakashi froze momentarily, then found himself immersed in a scarlet world.
"!?"
Kakashi was startled.
The transition was so seamless that his Mangekyo Sharingan offered no resistance, and he was already trapped in Shinji's genjutsu space.
"How is this possible!? My left eye is also a Mangekyo Sharingan. In theory, it should at least put up some resistance against a Mangekyo dojutsu!"
Kakashi analyzed silently.
Clearly, Kakashi in this timeline hadn't been instantly overwhelmed by Itachi's Tsukuyomi as in the original timeline, so he didn't realize that a Mangekyo Sharingan only offered resistance to genjutsu, not immunity against a powerful Mangekyo dojutsu like Tsukuyomi.
Moreover, Shinji's "Takamagahara" was a fusion of three Mangekyo dojutsu: Tsukuyomi, Jikibi, and Yachihoko.
In terms of sheer dojutsu strength, it surpassed Tsukuyomi.
So, for Kakashi to think he could resist "Takamagahara" with just his left eye's Mangekyo Sharingan was wishful thinking.
Still, Kakashi was an experienced elite. He quickly suppressed his shock and surveyed his surroundings.
Before him stretched a scarlet world.
Looking up, he saw a massive Sharingan shadow hovering in the sky, as if the entire world's crimson hue was projected from this spectral eye.
"Is that Shinji's Sharingan…?" Kakashi murmured.
Under such a striking scene, even Kakashi felt his heart waver.
He lowered his gaze, taking in his surroundings.
He stood on a vast platform, its edges shrouded in impenetrable mist. Approaching the edge, he saw the platform seemed to rise above a sea of fog, where a single misstep could lead to an abyss.
Suddenly, Shinji's voice came from behind: "This is my 'Takamagahara'!"
Kakashi turned to see Shinji's figure abruptly appear on the platform.
As Shinji strolled casually, he explained: "Here, I can control everything, including matter and time."
As if to prove his point, the flat platform instantly transformed into rugged mountains, then a canyon, a forest, a snowy plain, a river, a lake.
Each change happened in an instant, as if the world reshaped itself to Shinji's will.
Kakashi couldn't hide his astonishment.
When the surroundings turned into a lake, he crouched and picked up a snowball from the previous snowy plain, still in his hand.
What shocked him most was the snowball's chilling realism. Despite his experience, no method he tried could reveal it as an illusion.
Tossing the snowball into the lake and watching the ripples, Kakashi marveled: "This is simply unbelievable!"
Shinji smiled and continued: "Besides the environment, I can create any imaginary enemy—though they must be someone I've seen, ideally fought."
As Shinji spoke, shadowy figures appeared before Kakashi.
Kakashi's expression tightened as he recognized them.
Among the shadows were Shinji's ninja academy peers—Kurama Yakumo, Sasuke, Neji, Kimimaro—and even Akatsuki members, like Hiruko, who had completed the "Bloodline Fusion Ritual" and wielded five Bloodline Limits!
Pointing at Hiruko, Kakashi asked: "Shinji, can your dojutsu truly simulate Hiruko?"
Shinji replied: "A perfect replication is impossible, but I can achieve seventy to eighty percent accuracy. I can also freely enhance or weaken specific abilities of the imaginary enemy. So, if the simulation isn't precise, I can manually adjust to make it closer to the real thing."
After hearing Shinji's explanation, Kakashi had a revelation.
He had always thought Shinji seemed too at ease when facing Hiruko. His experience suggested only two possibilities: either Shinji's strength far surpassed Hiruko's, or Shinji knew Hiruko's tactics inside out.
Now, understanding "Takamagahara," he realized it wasn't Shinji's overwhelming strength but his use of "Takamagahara" to master Hiruko's techniques, making their real encounter seem effortless.
Eager to test it, Kakashi said: "Can I try? Let's go with Hiruko!"
"Of course!" Shinji waved his hand.
The other shadows vanished instantly, while Hiruko's figure solidified, becoming lifelike before Kakashi's eyes.
"This!?"
Kakashi had expected to face a mere shadow of Hiruko, but Shinji's dojutsu created a figure indistinguishable from the real Hiruko. Even with his most critical eye, Kakashi couldn't find a single flaw!
Stepping aside, Shinji asked: "Ready?"
"Yes!" Kakashi nodded.
With another wave from Shinji, the surroundings shifted from the lake to the scene of Hidden Leaf Village during Hiruko's first invasion, where Kakashi had confronted him.
The realism was so intense that Kakashi felt momentarily disoriented.
Shua.
As Kakashi was caught off guard, a gust of wind accompanied Hiruko's charge toward him!
Kakashi quickly focused and met the attack.
The moment they clashed, a familiar sensation hit him, and he thought: "This speed, this strength—it's exactly like Hiruko!"
Despite repeatedly raising his expectations of "Takamagahara's" power, only now, fighting the simulated Hiruko, did Kakashi realize he had still underestimated it. It felt like he was battling the real Hiruko.
Moments later, Kakashi raised his hand, signaling Shinji to stop.
Shinji instantly froze everything, including the fake Hiruko, poised to strike Kakashi.
Looking at the immobilized Hiruko, Kakashi panted and said: "This is incredible, absolutely incredible!"
Shinji smiled: "It's alright."
Kakashi hurriedly added: "With this, we can simulate battles against Akatsuki members. This could be invaluable for our final battle with them!"
Shinji nodded: "I know."
Kakashi grew more excited: "No, you don't understand. If we can spread this, our village's strength could rise to a whole new level!"