Susanoo is often described as the ultimate, forbidden power of the Uchiha clan—an avatar of destruction born from the Mangekyō Sharingan. This terrifying power, said to rival the strength of gods, can only be accessed by those who awaken the Mangekyō in both eyes.
Its manifestation is different for each user, influenced by their chakra, emotions, and individual abilities. Some are armored titans of wrath; others wield ethereal weapons or monstrous wings. But regardless of its form, Susanoo is feared. Few who have witnessed it ever lived to tell the tale.
For a long time, Uchiha Kai believed that he hadn't awakened his Susanoo simply because he wasn't strong enough. He assumed it was locked away, unreachable. But after recent revelations during his mission, he was stunned to realize the truth—it had always been there, dormant, waiting for the right trigger.
Susanoo is not a power that must be summoned from beyond; it is already within the user. Like a sleeping guardian deity, it dwells within the chakra and spiritual strength of those who bear the Mangekyō. The key to unlocking it isn't brute force or technique—but emotion. Intense, overwhelming emotion.
"The Mangekyō Sharingan itself is the key," Kei whispered to himself, wiping cold sweat from his brow. Even now, if he closed his eyes, he could still see that spectral form lurking in the darkness—a shadow in his vision.
He hadn't activated Susanoo in the traditional sense. Rather, he had begun to sense it, to connect with the overwhelming presence through his chakra network and spiritual power. As if the entity had acknowledged his awakening.
What struck Kei most was what he'd read in the fragment of Uchiha Madara's writings: that the chakra of the Sharingan is imbued with a specific Yin chakra—a spiritual force created not simply by mental energy, but by emotions pushed to the extreme. Not ordinary anger or fear, but love warped by tragedy, hatred forged through loss.
"The Uchiha are driven by emotion," Kai thought grimly. "That's what makes us dangerous. What makes us… unstable."
Kai had always interpreted Yin Release as a tool for illusion or mental attacks. But now, he saw it differently. What he felt during his awakening wasn't just Yin chakra—it was a manifestation of his soul, forged in the crucible of near-death experiences. When he'd fought Minato Namikaze. When he'd nearly been crushed by Loess. These moments brought him closer to the threshold.
But ever since those battles, Kai's emotions had cooled. He was calmer, more analytical. Detached.
"Maybe that's a problem," Kai muttered. "A calm Uchiha might be a dead Uchiha."
Still, even Madara had shown immense control in his later years, biding his time and waiting patiently for his plan to unfold. Susanoo wasn't bound only to chaos; it could be nurtured through will and purpose.
Kai began to form a theory—one that the likes of Uchiha Shisui might validate. Shisui rarely had time to refine his Mangekyō, but after being betrayed by Danzo and watching his ideals crumble, he still managed to manifest a partial Susanoo. Was that the breaking point? The collapse of everything he believed in?
And what of the Sharingan's Yin chakra? Kai suspected now that it wasn't about maintaining intense emotions all the time—but about the origin of the chakra. That core moment of trauma and transformation when the eyes were first awakened.
"This power... it doesn't just cost chakra. It costs your sanity," Kai thought.
Look at Madara: he went blind from overusing his Mangekyō. Sasuke, in the space of one day, used his up so violently it was nearly destroyed. Every activation of Susanoo drained more than energy—it corroded the soul.
Still, Kai couldn't help but feel... exhilarated.
He'd found the key.
Now came the real challenge: could he wield this power without destroying himself?
"I have work to do when I get back," Kai muttered. "The Uchiha clan needs to be dealt with. And then... Uchiha Shuu."
Forcibly awakening the Mangekyō in others was a dangerous path, but Kai was willing to walk it. He needed a compatible pair of eyes for the Eternal Mangekyō. But such awakenings came only through deep trauma.
That would come later. First, there were the cells—Hashirama Senju's cells. Orochimaru had to be intercepted, or Kai would have to cultivate his own team of medical ninjas to replicate the experiments.
"Without support, even with the data and samples, I'd have to implant the cells myself," Kai said with a grimace. "Might as well pull a Madara and carve a hole in my chest."
So many risks. So much danger.
And yet... the rewards outweighed them.
He'd already revealed his power once—when he helped break Obito's illusion. He couldn't afford to hesitate now. What was there left to fear?
With that thought, Kai finally let himself rest. His mind, stretched from the contact with Susanoo, finally relaxed.
By morning, he awoke refreshed. After a quick shower, Kai realized he was the last to rise. Kenta Imai and Aya Hyuga had already left the tent.
After dressing and buckling his sword to his hip, Kai stepped outside. To his surprise, only Aya and Kenta were there. No sign of Minato or Kakashi.
"Just the three of us?" Kai asked, frowning. "Where are Captain Minato and Kakashi?"
Hyuga Aya gave him a glance, her Byakugan calmly fading. "Captain Minato asked us to head out ahead. He's handling the aftermath with the Iwa-nin. He said to summon him with a signal once we're close to Konoha."
"Oh?" Kai smiled. "Looks like Captain Minato is planning a grand entrance."
No doubt, word had already reached Konoha via messenger hawk. Iwa had been forced into unfavorable terms. With the Third Tsuchikage likely needing time to respond, Konoha was riding a wave of victory.
Minato's star would rise—and so would Kai's, by association.
"In the original timeline," Kai mused, "Konoha's negotiators sold us out for peace. But this time... things are different."
Now, Minato wouldn't just be the Yellow Flash. He'd be the hero who broke Iwa.
"I imagine we'll all share in the celebration," Imai Kenta said with a sly grin. "Think of it, Kai—we'll be welcomed as heroes."
Kai nodded, but his thoughts were elsewhere.
The Third Hokage might be planning to retire. Danzo would stir from the shadows. Orochimaru would scheme. But this time, Uchiha Kai would not be a bystander.
The board was set. And Kai was ready to play.