Raiden knew Muzan had opened the Infinity Castle to buy time and recover.
Understanding this, Raiden's objective was simple. If he could locate Muzan before his recovery was complete and keep inflicting damage, Muzan would never regain his full strength. Even if Muzan possessed power beyond that of a Hashira, it would mean nothing if he could not use it properly.
The only real obstacle was Nakime, the one controlling the Infinity Castle.
If he could find her and kill her, the balance of this battle would shift instantly.
After a brief moment of weightlessness, Raiden used the force from his Red Clean Arrow to land steadily on a wooden platform. He looked around at the endless arrangement of doors and rooms, his expression calm but focused.
It was fortunate Nakime had no direct offensive ability. If she did, she might have been even more dangerous than Kokushibo within this space.
Raiden stood still, then closed his eyes and took a slow breath. He activated Beast Breathing, Seventh Fang: Spatial Perception. Invisible waves spread from his body like ripples, extending rapidly in all directions.
At first, everything seemed normal. But as the waves traveled farther, something felt wrong.
They were not simply being blocked. They were being twisted.
The space itself was distorting his perception, bending and reflecting it in unpredictable ways. The Infinity Castle functioned like a massive warped mirror, making it difficult to gather accurate information.
"So that's how it works," Raiden murmured. "The entire space is distorted."
With that confirmed, he crouched down and tested another idea.
Fixing his gaze on a wooden door ahead, he raised his right hand and snapped his fingers.
The door trembled.
Then it warped.
Its edges blurred, as if pulled apart by an unseen force. Strange light flickered behind it, unstable and uneven. The room beyond became hazy, like it was covered by a thin veil.
Raiden watched closely. This was not just simple spatial interference. Each room in the Infinity Castle had its own unique properties, and their connections followed complex rules rather than normal structure.
"Useful… but not perfect."
His eyes sharpened.
That snap had not been a simple gesture. It carried the power of Kyougai's Blood Demon Art.
Originally, Kyougai controlled rooms through drumbeats. After merging with it, Raiden had refined it into something simpler, finger snaps.
In ordinary spaces, he could forcibly shift a room's position even without full control.
But the Infinity Castle was different. Its structure was far more complex, and Nakime was actively controlling it.
Still, the result was promising.
At the very least, his ability could influence this space.
Raiden allowed himself a faint smile.
The strength of a Blood Demon Art depended on its user. And Raiden's power had long surpassed Kyougai's.
Judging from the reaction just now, he could eventually manipulate the Infinity Castle just like Nakime.
He only needed time.
Without hesitation, Raiden placed his palm on the floor. The subtle, grainy texture met his skin as his Blood Demon Art spread outward, attempting to merge with the castle itself.
Far away, Nakime sat atop a high platform, her biwa resting in her hands.
Suddenly, her aura surged.
Her long hair shifted without wind, revealing her face.
It was unsettling.
She had no eyes in the usual sense, no brows, no ridges. Instead, a single large eye sat above her nose, staring forward like a cold gem. Within its pupil, the character "Three" was clearly visible.
Her skin was pale, almost lifeless. Her sharp cheekbones and narrow chin gave her a harsh appearance.
As her hair moved, it twisted unnaturally, like dark snakes revealing her expression.
For the first time, her eye showed surprise.
Someone was interfering with the Infinity Castle.
Her grip on the biwa tightened, and a dangerous glint appeared in her gaze.
Who?
She felt a section of the castle slipping from her control.
Lowering her head slightly, her fingers brushed across the strings.
A low note rang out.
The entire Infinity Castle trembled.
Nakime could not attack directly, but she did not need to.
Muzan had filled the castle with demons for this exact purpose.
By shifting space and unleashing them, she could eliminate any threat.
Taking control from her would not be easy.
Her fingers moved again, producing an eerie melody. The sound spread quickly, carrying her intent across the castle.
At that moment, Raiden's ears twitched.
Something had appeared within his range.
Not approaching. Manifesting.
Then it came.
With a loud crash, as if space itself had split open, a door above him burst apart. A swarm of demons poured out.
They were grotesque.
Their bodies were twisted, limbs uneven and unnatural, as if stitched together without care. Pale skin stretched over their forms, covered in bulging blue veins that pulsed faintly.
Drool dripped from their fangs, thick and foul, hanging in strands that reeked in the air.
They roared as they lunged, claws tearing through the space toward him. Their eyes burned with madness and hunger.
The stench alone was suffocating.
Yet Raiden did not move.
He kept his hand pressed against the floor, continuing his fusion with the Infinity Castle. He did not even look up at them.
Nakime's reaction confirmed it.
He was on the right path.
If she was trying to stop him, it meant his control was taking effect.
Raiden's focus sharpened further.
Taking control of the Infinity Castle would give him a decisive advantage.