Uchiha Fugaku could not help crying out in surprise. Even the Sage of Six Paths had not lived that long.
"Yes. Once you become a demon, your lifespan is no longer limited, but that transformation also comes with fatal flaws."
Zongyan nodded in reply and began explaining the demons' weaknesses.
"All demons have to eat humans, and all of them fear sunlight. Exposure to sunlight kills them completely. Aside from that, their world also has a special kind of Nichirin Blade that can kill them."
At those words, Fugaku and Itachi instantly extinguished the trace of desire that had just arisen in their hearts.
Hearing about a thousand-year lifespan and an uncanny, immortal body that could heal itself had inevitably stirred them both.
But having to eat humans, dying upon exposure to sunlight, and having weapons specifically designed to counter them suddenly made it far less appealing.
Seeing their expressions, as though they had swallowed flies, Zongyan thought, The side effects really scared them off.
Still, he continued explaining the rest of that world's workings:
"And demon slayers rely on two main abilities: Breathing Styles and the Transparent World."
"A Breathing Style taken to its utmost can forcibly push the body to its limits, while the Transparent World lets them see through every movement and opening."
"Demon slayers who reach the pinnacle of their training have strength comparable to Kage Level fighters in the Shinobi World."
At that, Fugaku's and Itachi's expressions changed dramatically, their eyes filled with disbelief.
No chakra? They could attain Kage Level strength simply by pushing their bodies to the absolute limit?
This completely overturned everything they knew.
Looking at the stunned pair, Zongyan thought:
The power displayed during Shippuden was low. If you had seen the Blue Beast of the Hidden Leaf, you wouldn't be so surprised.
Before they could compose themselves, Zongyan revealed the price of possessing such great power.
"Although their bursts of power are quite formidable, all the fighters who reach the pinnacle and unlock the Transparent World completely exhaust their bodies. Almost none live past twenty-five."
"Of course, those born with a Demon Slayer Mark who unlock the Transparent World don't count."
In an instant, Fugaku and Itachi both fell silent as the same picture formed in their minds.
Without completely wringing out their bodies, they could not kill demons, yet doing so would shorten their lives.
"What a tragic world!"
Fugaku let out a long sigh, then furrowed his brow and fixed a sharp gaze on Zongyan, raising the most fundamental question.
"You just said you wanted to use this world to support the Uchiha, but from what you've told us, its fighters are no weaklings. The strongest demon slayers rival Kage Level fighters, and immortal demons lurk there too."
"With our clan's current strength, we simply couldn't do it, could we?"
This was no undue self-deprecation.
Powerful as the Uchiha Clan was, it was ultimately just one clan within Konoha, with only a handful of top-level fighters.
Recklessly entering an unfamiliar world to face Kage Level warriors and immortal demons could bring utter destruction with the slightest misstep.
Faced with his father's question, however, Zongyan shook his head.
"Father, you're overthinking it."
"The strong in that world are an extremely small minority, after all. Besides, they all remain in the shadows and can't interfere with how the world as a whole operates."
After saying this, he saw that the two still seemed somewhat confused, so he continued.
"That world belongs to ordinary people. They've established hundreds of countries, large and small, and ordinary people control the armies and wealth."
"Oh? You want to recreate what happened in the Land of Rice Fields in that world?"
Fugaku understood at once and voiced Zongyan's plan.
"Exactly!"
"Before our Sharingan, those so-called rulers don't even have a chance to resist."
Zongyan nodded, confirming his father's words.
"You mean that as long as we quietly take control of those countries' rulers and manipulate their minds with genjutsu, all the world's resources will be under our control?"
Uchiha Itachi had caught on as well and voiced the outcome he envisioned.
When Uchiha Itachi finished, he exchanged a glance with Fugaku. Before they had even begun, their hearts were already surging.
That was right. They were shinobi, Uchiha who possessed the Sharingan.
That world had no special energy and no shinobi, and ordinary people had no means of resisting genjutsu.
To ordinary people, the Sharingan was an unstoppable divine power.
They would not need to wage war or spill blood and sacrifice lives. With one genjutsu after another, they could take control of the entire world without bloodshed.
"As for those demons..."
Zongyan shifted the subject, a meaningful smile curling his lips. "They aren't entirely useless either."
"Demons are created from Muzan Kibutsuji's blood. Every demon is under his control and obeys him absolutely."
"As long as we control Muzan, we'll effectively have countless immortal fighters in our hands. Those demons could become the Uchiha's sharpest blade."
Fugaku's pupils contracted slightly. "Control Muzan? He's an ancient demon who has lived for a thousand years. His strength must be terrifying. How would we control him?"
Zongyan did not answer immediately. Instead, he turned toward Itachi beside him, a meaningful look in his eyes.
"To take down Muzan, we'll need you to step in, big brother."
Itachi paused, frowning as he briefly considered it.
Ordinary genjutsu would probably struggle to control an immortal demon who had lived for a thousand years.
They needed a top-tier genjutsu that could directly rewrite the will, ignoring the constraints of the flesh.
In the entire Uchiha Clan, and indeed the entire Shinobi World, only one person possessed such a power.
Itachi abruptly raised his head, understanding flashing in his eyes as he blurted out:
"Shisui?"
"Exactly!"
Zongyan nodded emphatically, his eyes gleaming.
"Kotoamatsukami can bypass all physical defenses and directly alter a target's innermost will. The victim won't even realize they're being controlled. They'll simply regard the altered thoughts as their own true desires."
"Muzan may have lived for a thousand years and possess an immortal body, but he still has a will and a mind."
"As long as Shisui uses Kotoamatsukami on him, Muzan will become our most loyal puppet."
"When that happens, all the countless demons under him will obey our commands. An immortal demon army that fears neither pain nor injury would be enough to sweep through any shinobi village in the Shinobi World."
The room fell deathly silent.
The candle flame crackled as Fugaku and Itachi rapidly weighed the plan's feasibility.
The plan was good, but its most crucial step depended on Shisui.
"But..."
Itachi spoke first, his brow tightly furrowed. "Shisui is still imprisoned underground, and his loyalties remain uncertain. The Will of Fire in his heart hasn't completely crumbled. How could he agree to help us use Kotoamatsukami to control a demon from another world and plunder resources for the Uchiha?"
Zongyan nodded. That was indeed the most immediate problem.
If Shisui was willing to cooperate, everything would be easy.
But if he would rather die than comply, he could not blame Zongyan for gouging out his eye and using it himself.
Zongyan did not say that aloud. Instead, the corners of his mouth lifted slightly as he continued persuading Itachi.
"That's why I need you to put more effort into it, big brother."
"The demon slayers and demons in the other world are still fighting. We have plenty of time."
"You're the person Shisui trusts most. Talk to him patiently and dismantle his fixation little by little."
"Only when he fully comes to his senses and is willing to fight for the clan will that divine weapon, Kotoamatsukami, truly be ours to use."
Itachi was silent for a moment before slowly nodding.
"I'll do my best."
Seeing Itachi agree, Fugaku and Zongyan both nodded in satisfaction.
Winning Shisui's allegiance would not happen overnight. They could not rush it.
Fortunately, the plot of the Demon Slayer World had only just begun, and the final battle in Infinity Castle was still a long way off. For now, they could watch the two sides fight and patiently wait for a badly weakened Muzan.
The atmosphere in the room eased slightly.
Zongyan's gaze shifted subtly. Raising his hand, he tapped the air, selecting the Sub-Multiverse Portal belonging to the Demon Slayer World in his inventory.
An inky light shimmered before the three of them, and a person-sized wooden portal slowly materialized in front of them.
Its frame was made of dark wood, with no unnecessary carvings on its surface. Only the center of the door carried a flowing layer of inky luster, rippling gently like water.
Fugaku and Itachi stood up at the same time, their eyes filled with shock.
"This is... a portal to another world?"
Fugaku stepped forward and reached out to touch the wooden door, only to stop half an inch away, afraid of disturbing something.
Itachi walked around the wooden door, carefully examining its patterns, his eyes brimming with curiosity and wonder.
"This is unbelievable..."
He murmured under his breath, "I can't sense any chakra fluctuations at all. How does this even work?"
Zongyan smiled without explaining, because he did not understand either.
He raised a hand and patted the portal leading to the Demon Slayer World, looking at the two with burning eyes as a sharp smile curled his lips.
"Father, big brother."
"Now that we've settled on a plan, shall we... take a trip to the other world right now?"
Fugaku and Itachi exchanged a glance, each seeing resolve and anticipation in the other's eyes.
"All right! Once I've left a letter for your mother and the Clan Elders, the three of us will set off!"
Fugaku took a deep breath and agreed.
Before you continue