The abilities of Mangekyo dojutsu are not set in stone—this is something Shinji understood better than anyone.
Take his Susanoo Tomoshibi, for example. During his Mangekyo Sharingan days, it could only manifest two pairs of eye sockets, meaning it could only control one additional pair of eyes besides his own Mangekyo Sharingan.
But after Shinji fused his eyes to awaken the Eternal Mangekyo Sharingan, his enhanced dojutsu power allowed Susanoo Tomoshibi to manifest three pairs of eye sockets, granting him not only the ability to control two pairs of eyes simultaneously but also the power to forcibly merge two pairs of eyes using his dojutsu.
It could be said that the step from Mangekyo Sharingan to Eternal Mangekyo Sharingan brought a near-qualitative leap to Susanoo Tomoshibi.
The same applied to Jikibi and Wazunagi.
During the Mangekyo Sharingan phase, he could only sustain a half-body Susanoo, but with the Eternal Mangekyo Sharingan, he could unleash a complete Susanoo!
Mumei's Yachihoko, even at the Mangekyo Sharingan stage, could transfer the recorded powers of Jikibi, Wazunagi, and Susanoo Tomoshibi—at their Mangekyo-level strength—into Shinji's Rinnegan.
Thus, Shinji could reasonably deduce that if Mumei obtained a pair of Eternal Mangekyo Sharingan, the power of Yachihoko would undoubtedly reach a new level.
At that point, anything could be possible, so Shinji wasn't in a rush!
To test his hypothesis, Shinji brought Mumei to an underground training ground.
In the training area, Shinji activated Susanoo again, sparing no dojutsu power as he launched attacks on various targets.
Before long, the dojutsu power that Mumei had infused into him via Yachihoko was depleted.
And with the exhaustion of his dojutsu power, not only could he no longer sustain Susanoo, but the three Magatama on his Rinnegan vanished as well.
"They really disappeared…"
Mumei sighed.
Shinji said, "Your Yachihoko is currently like a massive aggregator, capable of gathering everyone's chakra together. But limited by its Mangekyo-level power, this chakra is merely collected without undergoing any qualitative change or Yin-Yang fusion. It's essentially just a gathering of quantity."
Mumei asked, "So I can't truly return your dojutsu to you?"
"Hm!" Nodding, Shinji continued, "This simple aggregation of chakra doesn't elevate your own level, so you can't truly return those dojutsu to me in any meaningful way!"
After Shinji's explanation, Mumei finally gained a comprehensive understanding of her own abilities.
During the Warring States period, the Mangekyo Sharingan was already the pinnacle of the Uchiha clan's power. Including Mumei herself, the entire clan didn't know how to further enhance dojutsu power, so they resorted to the crude method of implanting dojutsu into her through techniques.
But in the era of shinobi villages, especially with the development of medical ninjutsu and various biological cell technologies, shinobi had made significant strides in understanding the human body.
Whether it was the orthodox method of fusing a blood relative's Mangekyo Sharingan to awaken the Eternal Mangekyo Sharingan, or the unorthodox method like Hiruko's Bloodline Fusion Ritual, both could genuinely enhance dojutsu power.
Thus, Mumei, who was seen as a decisive weapon by the Uchiha clan a hundred years ago, held even greater potential in the current era.
Shinji even entertained the idea of using Mumei's Yachihoko to gather the chakra of the entire shinobi world to confront the Hegemon of Terror in a final battle.
Before this, gathering the chakra of the entire shinobi world required the exhausting task of reviving the Ten-Tails and risked Kaguya Otsutsuki hijacking the process through Infinite Tsukuyomi.
Now, with Mumei's Yachihoko, it seemed a simpler solution was possible—at the very least, a viable backup plan!
After some thought, Mumei said, "Shinji, I'm ready. Enhance my dojutsu power! Once my dojutsu power improves, I can truly help you!"
Shinji asked, "Aren't you worried I might use you?"
Mumei answered directly, "You're the only person in this world who cares about me, who values me! So even if you wanted to use me, I'd be willing!"
Shinji wanted to tell Mumei that the Hegemon had set its sights on the shinobi world, that the world was already in crisis. But meeting her clear, earnest gaze, he couldn't bring himself to say it.
"Let her enjoy some happiness for now and find the right moment to tell her later," he decided silently.
First, Mumei's life had been too tragic. Now that she was finally finding some peace, there was no need to immediately plunge her into fear of the future.
Second, Shinji didn't want to use the threat of the Hegemon to pressure Mumei.
Seeing Shinji's silence, Mumei quickly asked, "What should I do next?"
Shinji said, "Don't think too much about it for now. Your top priority is to condition your body. Everything else can wait."
Mumei asked, "How long will that take? I feel like I'm in great shape right now. I don't think I need any more conditioning!"
Shinji shook his head. "That's just an illusion. Because of Yachihoko, you're always in a state of abundant chakra, which clouds your perception and makes you overlook the real issues in your body. You need to be mindful of this going forward!"
"Oh!"
Shinji thought for a moment. "But since you just completed a short-term rest, your body has recovered to some extent. So before your next rest, you can relax for a few days. How about this? Let's take this chance to visit Hidden Leaf Village!"
Mumei's eyes widened. "Really?"
Shinji laughed. "Of course it's real. But you have to promise me you won't use your Sharingan recklessly."
Mumei nodded repeatedly. "Don't worry!"
Without wasting a moment, Shinji had Mumei change into casual clothes and took her toward Hidden Leaf Village.
Due to a recent funeral, the village streets felt somewhat somber. The villagers' faces were mostly marked with sorrow, lacking the usual chatter and laughter. But even so, to Mumei, Hidden Leaf was bustling beyond imagination.
Having lived in the Warring States period and spent most of her time confined in her clan's dungeon, she had only seen small hamlets. Let alone a city-level super shinobi village like Hidden Leaf—she had never even seen a town.
"Shinji, what's that?"
"That's a dango shop!"
"What's a dango shop?"
"They sell dango, a kind of snack! Uh, never mind, I'll buy you a skewer. You'll understand once you try it!"
After leaving the dango shop, Mumei savored the taste of the three-colored dango while pointing into the distance. "Shinji, Shinji, what's that place?"
"A barbecue restaurant!" Pausing, Shinji cut off her next question. "Don't ask. You'll know once you eat. Let's go!"