"Domain Expansion: Unlimited Void."
It sounded incredibly impressive, but the effect was actually quite simple: it forcibly flooded the opponent's brain with an infinite amount of useless information until their cognitive system collapsed.
In just 0.2 seconds, it could force half a year's worth of meaningless information into the target's mind.
Anyone subjected to that would have their brain shut down.
Gojo Satoru floated at the centre of the domain, looking at Abe no Seimei with a faint smile.
At that moment, Abe no Seimei stood completely motionless, as though he had lost the ability to think.
As expected, I'm the strongest.
With that thought, Gojo stepped forward and approached Abe no Seimei, intending to deliver the final blow.
However, just as he prepared to attack, Abe no Seimei's vacant eyes suddenly became more alert than ever.
Gojo was startled and instinctively retreated.
But it was already too late.
A dazzling flash of blade light swept past.
Gojo's domain instantly collapsed. A wound deep enough to expose bone stretched across his upper body, while pitch-black yokai energy spread from the injury towards his limbs.
"How… is that possible…?"
Gojo could hardly believe that his domain had failed to produce any effect whatsoever.
"You are far too arrogant, Six Eyes."
Abe no Seimei held the Demon King's Mallet that had wounded Gojo and looked calmly at him.
"No matter how powerful Unlimited Void may be, it is still merely a domain."
Hearing this, Rowan secretly nodded.
Just as Abe no Seimei had said, no matter how powerful Unlimited Void was, it was still only a domain.
And one that attempted to fill the opponent's brain with useless information.
It sounded terrifying, but there were actually many ways to counter it.
Rowan had seen everything clearly.
The reason Abe no Seimei had been unaffected by Unlimited Void was because he had established a barrier around himself that blocked the useless information being forced into his mind.
As a result, Unlimited Void lost its intended effect.
Of course, not every barrier could accomplish such a thing.
But Abe no Seimei was different.
He was not only a great onmyoji, but also the progenitor of jujutsu sorcerers and an expert at manipulating barriers.
Creating a barrier capable of resisting Unlimited Void was hardly difficult for him.
"Farewell, Six Eyes."
Looking at Gojo, who was kneeling on one knee, Abe no Seimei swung his blade again.
The sharp blade light instantly split the air and ground before Gojo in two.
Just as it was about to split Gojo himself—
Whoosh!
A piercing sound tore through the hall of Aoi Spiral Castle.
A crimson demonic spear arrived after the blade light had been launched, yet struck first, accurately shattering Abe no Seimei's attack.
Gojo raised his head.
A blue figure descended from above and landed in front of him.
"Hey, white-haired brat."
Cú Chulainn straightened his body and rested the terrifying Gáe Bolg over his shoulder. His long blue hair fluttered in the violent aftermath of the yokai energy.
He turned his head and gave Gojo a wild grin.
"You stole the first turn from me. It should be my turn now, right?"
Gojo looked unwilling, but there was nothing he could do.
He attempted to heal himself with Reverse Cursed Technique, but the results were unsatisfactory.
The technique did indeed heal his wound.
However, a mass of pitch-black yokai energy remained inside his body, and he could not remove it no matter what he tried.
Under its influence, Gojo could not even exert half of his normal strength.
Let alone continue fighting Abe no Seimei.
If he kept going, how would that be any different from willingly throwing away his life?
Seeing Gojo's unwilling expression, Cú Chulainn could not help laughing loudly.
He turned towards Abe no Seimei.
"Hey, it's my turn now. Are you ready to get beaten?"
Abe no Seimei narrowed his eyes and paid no attention to Cú Chulainn's taunting.
He held the Demon King's Mallet before himself and said expressionlessly, "A barbarian human… It matters not. I will simply cut you down."
"Then give it a try, bastard!"
Cú Chulainn laughed and suddenly kicked off the ground.
His speed was faster than teleportation.
The demonic spear transformed into a bolt of crimson lightning and thrust towards Abe no Seimei.
Every strike carried a curse.
Every attack was destined to pierce the heart.
Abe no Seimei blocked with the Demon King's Mallet.
The demonic blade and spear collided, their sparks tearing black cracks through space.
After repeatedly failing to force Cú Chulainn back, Abe no Seimei retreated half a step and sent five paper talismans flying from his sleeve.
"Five Elements Mutual Restraint: Demon-Sealing Barrier."
"A barrier?"
Cú Chulainn performed a backflip to create distance, spinning the demonic spear in his hands.
"I hate you people who keep drawing circles!"
He poured all his magical energy into the spear and aimed its point towards Abe no Seimei.
"In that case, don't blame me for getting serious. I'll be taking your heart."
"Pierce—
Gáe Bolg!"
At that moment, cause and effect were reversed.
It was not that the spear pierced the heart.
Instead, the result that the heart had already been pierced was determined first, and only then did the spear tear through space and distort causality.
It transformed into an unavoidable streak of crimson lightning aimed directly at Abe no Seimei's chest.
Within Abe no Seimei's pupils was reflected the demonic spear destined to pierce everything.
The causality-reversing crimson spear penetrated space, tore through the Demon-Sealing Barrier, and touched Abe no Seimei's robes.
Yet Abe no Seimei did not dodge.
He did not even raise his blade to block.
He allowed the spearhead to enter his chest and pierce straight through his heart.
"Causality reversal? An impressive technique."
Even with his heart pierced, Abe no Seimei's voice remained as calm as still water, without the slightest ripple.
"But you made one mistake, barbarian."
Cú Chulainn's smile immediately froze.
He clearly saw that after the spear pierced Abe no Seimei's heart, what flowed from the wound was not blood, but writhing, pitch-black yokai energy.
Countless tiny tendrils of flesh emerged from the edges of the wound and intertwined at a visible speed, stitching the injury closed.
Within three breaths, the hole through his heart had vanished completely, as though it had never existed.
At the same time, Abe no Seimei's voice continued.
"For humans, the heart may be a fatal weakness. But I surpassed humanity long ago. Therefore…"
The next instant, the Demon King's Mallet swept horizontally.
Cú Chulainn yanked his spear free and retreated.
The shaft released an unbearable groan beneath the demonic blade's strike.
He was forced back more than ten metres, the soles of his boots ploughing two trenches through the shattered stones.
Before he could regain his footing, densely packed cursed markings suddenly lit up beneath his feet.
He looked down.
An enormous cursed formation covering a hundred-metre radius had already activated.
"Onmyodo: Soul-Binding Barrier."
Abe no Seimei's voice echoed from every direction at once.
Countless chains burst from the formation and wrapped around Cú Chulainn's limbs, torso, and neck.
"My heart is not a weakness."
After saying those final words, Abe no Seimei raised his demonic blade and prepared to deliver a fatal strike.
However, the instant the blade descended, an arrow struck its side.
The power carried by the arrow erupted violently, forcing Abe no Seimei backwards.
At the same time, it tore apart the barrier and freed Cú Chulainn.
Heroic Spirit EMIYA had acted.
"Tch."
Cú Chulainn spat out bloody saliva and looked up at the figure with a grin.
"I owe you one."
"You were too careless," EMIYA calmly said. "You must remember that your opponent is an ancient monster who has lived for over a thousand years."
Given a thousand years, even a pig could become a supernatural creature.
Let alone Abe no Seimei.
He had been someone capable of leaving behind extraordinary achievements in history after living only a few decades.
Who knew how powerful he had become after a thousand years?
Cú Chulainn fell silent.
"…Fine. I was careless. But it won't happen again."
He tightened his grip on the demonic spear and aimed it at Abe no Seimei's head.
"My next strike will target your skull."
He refused to believe this man could survive after having his head blown apart.
Abe no Seimei did not care about Cú Chulainn's provocation.
Instead, he slowly said, "That should be enough. It is time."
Cú Chulainn let out a confused "Huh?" and gave him a look that clearly asked what the hell he was talking about.
At the same time, something strange occurred inside Spiral Castle.
Near and far, in every direction, countless ghostly blue flames lit up within the darkness.
EMIYA's pupils contracted, and he abruptly raised his head.
A figure appeared within every flame.
They wore onmyoji robes of various colours and rode upon shikigami, surging towards the hall of Aoi Spiral Castle like a tide from every direction.
Nearby, a white-haired young man descended from above while standing upon an enormous canine shikigami.
When he landed, a fierce vortex of spiritual energy erupted around him.
In the distance, a gloomy-eyed middle-aged man emerged from the shadows. He carried an undying lantern, while a dense procession of yokai followed behind him.
In the north-east, a squad of onmyoji dressed in black advanced in formation, their talismans weaving into a sealing net in the air.
In the south-west, a female onmyoji wearing magnificent hunting robes rode upon a white fox and black panther. Yokai energy and spiritual power intertwined into countless threads across the sky.
South-east, north-west, due south, due north—
onmyoji arrived from every direction.
Shikigami roared from every side.
These people were the forces Abe no Seimei had accumulated over the past thousand years.
The Abe clan dressed in white.
The Gokadoin clan dressed in black.
In Nura: Rise of the Yokai Clan, nearly all of these people were Abe no Seimei's descendants.
They had achieved immortality through the Taizan Fukun Ritual created by Abe no Seimei.
They had only one purpose: to protect Seimei's throne and sacred land while awaiting his resurrection and return.
For this reason, they always remained beside the rulers of each era, serving as their personal onmyoji.
Although they rarely appeared on the stage of history, their power was said to surpass even that of great yokai.
The head of the family changed whenever history underwent a dramatic shift.
Beginning with the fifth generation, the family name changed from Abe to Gokadoin, and their clothing changed from white to black.
The Gokadoin family's magical formations took the shape of multi-pointed stars.
And in this chaotic crossover world, these people still existed.
They had been hiding inside Spiral Castle all along.
The battle between Gojo Satoru, Cú Chulainn, and Abe no Seimei had alerted them long ago.
However, they did not immediately appear.
Instead, they silently gathered their power and arranged their barriers.
Once every preparation was complete—
they finally revealed themselves.