"Upper Moon One... Kokushibo!"
Rengoku said in a deep voice.
"Has he finally appeared? The strongest Upper Moon!"
Tengen licked his lips, his eyes flickering with excitement and wariness.
The Pillars all wanted to advance and surround this one of the Demon Slayer Corps' greatest sworn enemies.
They knew that Kokushibo's strength was unfathomable, far beyond what Doma could compare to, and fighting him one-on-one would be absolutely hopeless.
However, just as they were about to act, Phaethon raised his hand to stop them.
"There's no need."
Phaethon's voice rang out calmly: "To deal with him, you don't need to intervene."
The Pillars were stunned and looked at Phaethon with some confusion.
Phaethon didn't explain, but simply turned his gaze to Miko Yotsuya, who had been somewhat nervous beside him.
"Miko."
He spoke gently: "Do you remember your ability?"
"Eh? My... my ability?"
Miko was somewhat bewildered, then remembered her magic [Spirit Control].
"Yes."
Phaethon nodded, pointing to Kokushibo on the high ground.
"Now let you try using your power to deal with him."
"Me?! Deal with him?"
Miko was startled, her small face instantly turning pale.
Make her deal with that six-eyed monster who looked terrifying and emanated a powerful aura?
She... she was just a LV1 newcomer!
"Don't be afraid, Miko."
Phaethon's voice carried reassuring power.
"You just need to do as I say, concentrate your mind, expend your magic power, and call out a name..."
He slowly spoke that name that had been sealed away for so long, yet still rang out like a legend: "Yoriichi Tsugikuni."
"Yori... ichi Tsugikuni?"
Miko repeated this unfamiliar name in bewilderment.
But the moment she spoke this name, she could feel the magic power and mental energy within her body being drawn out at an unprecedented speed!
An invisible force, following her will, crossed the boundaries of time and space, reaching into the realm of the dead!
On the high ground, Kokushibo's originally cold face.
The moment he heard the name Yoriichi Tsugikuni, his expression suddenly froze!
Those six eyes suddenly contracted, revealing disbelief, shock, and a hint of deeply hidden fear!
This name... this name he had been jealous of, hated, and feared all his life!
How could it be spoken from these people's mouths?
The next second, a scene that everyone, including Kokushibo himself, would never forget occurred!
Before Miko, the air began to distort, countless tiny points of light gathering from nowhere.
A vague human silhouette gradually became clear, finally condensing into a man wearing a red-based black-trimmed kimono.
With sun-shaped paper earrings, holding a crimson Nichirin blade.
His face was calm, yet his eyes burned with an inextinguishable flame!
He stood there quietly, emanating an aura as blazing and warm as the sun.
As if his very existence could dispel all darkness and eeriness in this Infinity Castle!
"Yoriichi Tsugikuni?"
Looking at this all-too-familiar figure before him, Kokushibo completely lost his composure!
His face, covered with demon marks, was filled with absolute horror, his voice distorted with excitement!
"Impossible! You... you're already dead! Dead for over a hundred years! How could you still appear here?!"
The summoned Yoriichi Tsugikuni simply looked calmly at his brother who had lost composure on the high ground.
In the depths of those flame-like burning eyes, there was no surprise, only endless resentment and an indescribable sorrow.
He didn't say much, just turned around and faced Miko who had summoned him.
He nodded slightly as a gesture of acknowledgment.
Then he turned his gaze back to Kokushibo, his expression becoming extremely sharp, filled with the resolve to cut through everything!
"Moon Breathing... how pitiful, elder brother..."
Yoriichi murmured once, then without hesitation, suddenly raised the crimson Nichirin blade in his hand!
"Sun Breathing!"
Blazing flames instantly wrapped around the blade, illuminating the entire platform like daylight!
Kokushibo felt that familiar yet fearsome power, forcibly suppressing the shock and panic in his heart, and immediately drew the demon blade at his waist.
"Moon Breathing!"
Eerie purple crescent-shaped sword energy surrounded his body, facing off against that blazing Sun Breathing!
Even though he had become a demon, possessing physical capabilities and regenerative abilities far beyond humans!
Even though he had practiced Moon Breathing for hundreds of years, believing he had transcended mortal limits!
When facing this brother who was like the sun incarnate, Kokushibo still felt an irrepressible fear and helplessness from the bottom of his heart!
"Elder brother, take this!"
Yoriichi moved!
He didn't use any complex techniques, merely stepped forward and delivered the most basic slash!
However, this seemingly simple strike seemed to contain the most yang and strong principles of heaven and earth!
Where the blade passed, space itself seemed to ignite, leaving blazing trails!
"Moon Breathing, First Form: Dark Moon, Evening Palace!"
Kokushibo roared, also swinging his blade to meet it, purple crescent sword energy tearing through the air!
Boom——!!!
Sun and moon shining together! Ice and fire colliding!
Two completely different top-level sword techniques clashed fiercely in the air, erupting in deafening roars!
However, just from the first exchange, victory and defeat were already clear!
That seemingly powerful purple moon sword energy, the moment it contacted the blazing Sun Breathing, quickly dissipated like melting ice and snow!
Yoriichi's crimson blade, unstoppable, cut through the moonlight's obstruction and continued forward!
"Splash——!"
Kokushibo couldn't even see the blade's trajectory, only feeling a coolness at his neck, then the world spun!
In his vision, the last thing he saw was his own headless body, and his brother's face that remained calm yet carried endless disappointment.
Thud.
Upper Moon One Kokushibo's head rolled to the ground, his six eyes still wide open, filled with unwillingness and disbelief.
This Pillar who had once caused heavy casualties to the Demon Slayer Corps, standing at the pinnacle of the Twelve Demon Moons, the strongest Upper Moon.
Had actually... actually been decapitated so easily in just a few moves?!
With Kokushibo's death, Yoriichi's figure also began to become ethereal, gradually dissipating like bubbles under sunlight.
Before completely disappearing, he looked one last time at his brother and sighed softly.
Finally transforming into points of light, returning to nothingness.
The entire platform fell into an eerie silence.
Whether the Pillars of the Demon Slayer Corps or the remaining demons, all were completely stunned by this mythical scene before them.
Upper Moon One... just died like that?
Instantly killed by a spirit summoned by a seemingly gentle and weak girl?
Everyone's gazes involuntarily focused on that black-haired girl still in shock and bewilderment—Miko Yotsuya.
Their eyes filled with complexity, shock, and an indescribable awe.
Originally thinking that this girl who had been following the deity was just an ordinary maid or passerby.
They never expected she would possess such terrifying... spirit summoning power?
Phaethon calmly observed all this, his face showing a satisfied smile.
He could clearly sense that after Yoriichi successfully killed Kokushibo.
As the user of the skill [Spirit Control], Miko had also gained a considerable amount of experience and power enhancement.
This clearly confirmed his speculation—his Familia members could not only adventure and level up in Orario's dungeon in the future.
They could also come to these other worlds and gain experience and power through battle!
And compared to Orario's dungeon with its heavy restrictions and other deities watching covetously.
These other worlds where he could use his power without any restraint might be more conducive to the rapid growth and leveling of his Familia members!
A completely new, broader leveling map was slowly unfolding before Phaethon...