'Black Blood Brambles!' Muzan unleashed countless long, barbed tendrils with his head still severed.
At the same moment, Gyomei's figure materialized behind Muzan, hidden by the power of the concealment talismans. His spiked iron flail whirled at an astonishing speed before he sent it crashing into Muzan, shattering his severed head and pulverizing half of his torso.
"Nice attack, Gyomei-san," Ryou acknowledged as he quickly scanned Muzan's body using his Transparent World. Only two hearts and one brain remained active.
Just then, the other Hashira arrived at the scene, their faces reflecting horror and worry as they took in the burning ruins of the Ubuyashiki mansion and saw Ryou and Gyomei fighting a man.
'Fifth Form: Lightning Storm!'
In a flash, Ryou blitzed toward Muzan, his Nichirin blade slicing through the blood tendrils like paper. He closed in on Muzan, his blade just inches away from landing a fatal blow targeting his other two hearts and brain, when the sound of a biwa resonated through the air.
Suddenly, a human-like demon materialized next to Muzan, extending his hand.
"Blood Demon Art: Gravity Push!"
A tremendous force crashed into Ryou, sending him skidding across the ground. He quickly regained his balance, his eyes narrowing as he looked at the human-like demon.
The demon had pale white skin, claws, and two curved horns jutting from his head. This wasn't an ordinary demon—Ryou sensed the power of the Upper Moon demon.
'A new demon? And it possesses the Blood Demon art of gravity? It seems Muzan has made some preparations before coming here, unlike in the original timeline. Is it because of my presence?' Ryou narrowed his eyes.
At the same time, Muzan's body regenerated, his once-pulverized form now restored. Looking at Ryou, he exuded an intense, malicious aura, enough to suffocate the air around him. "It's you...Nature Hashira Ryou."
"It's Muzan!" Gyomei's booming voice warned the newly arrived Hashiras. "Cutting off his head isn't enough to kill him!"
Hearing his words and the sight of Muzan for the first time left the Hashira momentarily stunned. However, without hesitation, they drew their katanas and launched their strongest Breathing forms, as they dashed toward Muzan.
Surrounded on all sides, Muzan's lips curled into a mysterious grin. Just as the Hashira prepared to strike, the sound of a biwa resonated through the battlefield again. Beneath everyone, sliding doors appeared, revealing the Infinity Castle.
The ground vanished, and without footing, the Demon Slayers found themselves plummeting into the depths of the Infinity Castle.
The demon who had earlier used his Blood Demon Art to stop Ryou from killing Muzan returned to his side. Then, alongside Muzan, he too leaped through the sliding door and vanished into the castle.
If he wanted, Ryou could easily avoid falling into the sliding door beneath him, given his speed and reflex, but wasn't he waiting for this very moment? He willingly allowed himself to fall through the door, along with the other Hashira.
As they descended, he glanced at Kanae, who was a short distance away from him in the free fall. His voice cut through the wind as he called out, "Be careful, Kanae."
Hearing his words, Kanae smiled softly, her eyes reassuring him not to worry.
Though he warned her, Ryou wasn't deeply worried. He knew Kanae's strength, she was strong enough to face Upper Moon demons like Doma without losing.
---
Ryou landed lightly on the wooden floor as the Infinity Castle morphed into a house-like structure around him. Immediately, an overwhelming swarm of demons, nearly 100 in number, surged toward him from all directions.
It was clear these demons were stationed here just to deal with him or wear him down.
'Nature Breathing...' Ryou muttered under his breath, his body becoming a blur as he dashed through the horde of demons. In mere seconds, every demon turned to ash, disintegrating into the air as if they had never existed.
Each demon was as strong as a Lower Rank, created with the purpose of wearing down the demon slayers. But against Ryou, they didn't stand a chance.
As he killed the demons, Ryou heard a chime of system notifications in his mind. He called up his status panel to check the number of demon points he has:
[~
Name: Ryou
Physique: Nature [Advanced - 42%]
Skill: Nature Breathing - Proficient [1/500], Tekkai [Max], Sharingan [Not upgradeable], Transparent World.
Demon Points: 400 ~]
He saw his demon points had climbed to 400, just 100 short of what he needed to fully max his Nature Breathing proficiency.
Closing his status panel, Ryou strode through the seemingly endless halls of the Infinity Castle, cutting down every demon that crossed his path. The castle itself twisted and shifted, trying to disorient and crush him, but nothing it did could stop his advance.
Suddenly, his Kasugai crow, with a talisman tied around its body, appeared overhead and delivered a message: Kanae had encountered Upper Moon Two, Doma.
'Is it Fate or...' Ryou thought, his eyes narrowed. Though Kanae was strong, his instincts wouldn't let him rest easy as she was facing Doma alone. His love for her couldn't help but make him worry.
'Why do I have a bad feeling about this...' Without wasting time, he instructed his crow to lead him to Kanae and dashed forward, activating his Nature Mode. A surge of powerful energy coursed through him as he tore through the castle, destroying the walls and corridors in his path.