From our brief exchanges, I was forced to bitterly acknowledge that Kokushibo was the better swordsman. Our attacks were devastating everything around us, forcing Muichiro and Tamayo to retreat toward another Demon Slayer that I had only just noticed. 'Genya, I think his name was… Sanemi's younger brother.' I noted, as I blocked a slash headed in their direction.
Currently, we were deadlocked, our katanas clashing relentlessly. Kokushibo broke the silence. "How are you alive?"
We separated briefly, only to clash again, our blows moving faster than the eye could follow. "I don't understand the question." I replied as his katana changed shape, growing slightly longer with three additional blades that were almost the length of my arm. He attacked again, pushing me back.
"I can see inside you. Your right side is destroyed, fractured ribs, a barely functioning liver, and the same for your spleen. So I'll ask again, how are you alive?"
I dodged an overhead strike that split the ground, countering with a piercing thrust that he deflected. "It's nothing more than a scratch." I didn't want to talk about the wound, it brought up not fond memories. But Kokushibo clearly didn't like my answer.
"Is that so? Then I wonder if your head being separated from your body would be considered a scratch."
I dropped into an iaido stance as he took up his own.
"Tenth Form: Drilling Slashes, Moon Through Bamboo Leaves." He created three rotating, saw like slashes with moon shaped blades trailing their paths. I gave Muramasa a small amount of my lifeforce.
"Soul-Rending Flash: Twilight Requiem." The air around Muramasa's blade darkened briefly before unleashing a powerful shockwave slash that met Kokushibo's attack head-on.
The attacks struggled against each other before exploding, sending a shockwave that forced us both back. I skidded to a stop beside Tamayo, Muichiro and Genya. When I looked, I saw that Gyomei and Sanemi had arrived.
"Ryou-san, let's fight together." Gyomei offered, but I shook my head as I turned back toward Kokushibo, who was just recovering from the shockwave.
"I'll be fine! Find the others and help them. Tamayo, go with them in case someone needs medical attention. I'll catch up once I'm done here."
As Kokushibo's aura grew even denser, I turned back to give them a reassuring smile. "I'll be fine, I have a daughter to get back to." Reluctantly, they nodded and retreated.
Kokushibo blitzed toward me, and I met his speed using Shundō, channeling cursed magic through my body and Muramasa. We collided once more, and he questioned me again.
"How are you able to fight me without using a breathing style? What do you gain from this?"
I raised an eyebrow as I countered a slash that nearly took my arm. "I'm just that strong, that's why. And what do I gain? A better future."
He scoffed as our blades clashed again.
To anyone watching, I knew we were likely no more than blurs with shockwaves marking our rapid movements. Kokushibo spoke again, his voice sounding distant, almost introspective. "I strived to surpass him…"
'Is this going to be a backstory?' I thought, feeling a surge of impatience at the idea of him monologuing mid-battle.
"I'll be respectful in saying." I interrupted, using "Cursed Slash" against him. He countered with one of his forms, our attacks nullifying each other. "I don't really care what's happened in your life. What matters is what you do now."
I launched forward, using Shundō faster than ever by pushing more cursed magic into the move, which caught him off guard. I brought my blade down and sliced his head clean off.
'Note to self: Repeated use of higher-level Shundō strains the tendons.' I noted, but it wasn't a big problem, just something for me to remember.
I started walking away from Kokushibo's body, hoping to catch up with the others. 'Hope everyone's okay.' I thought, feeling a bit tired. Suddenly, I heard the faint sound of fabric shifting. Sighing, I turned back toward his body, noticing his head was already beginning to regenerate. 'Of course.'
Turning fully, I used Shundō to close the distance. Blades began sprouting from his body, forcing me to pull back as he finished healing. Kokushibo cracked his neck as he looked at me.
"Fighting me now would be pointless, Ryou. Only the sun can harm me."
I scoffed, charging Muramasa with cursed magic. "Is that so?"
He extended a hand toward me, making me cock an eyebrow.
"Join us. Become a demon. You'll be able to leave a legacy beyond anything you can imagine. I'd even teach you my breathing style."
I lowered my stance, ready to burst forward with Shundō. "I'll have to pass on becoming a demon, I couldn't care less about legacy." I launched toward him, and he responded in kind. Our blows connected, forcing me back slightly. 'Seems this transformation wasn't just for show.'
I ducked under a slash and aimed for his torso, my blade slicing him in half before he healed instantly as it exited the other side. Reversing my grip, I countered his next strike.
"You can't beat me now, Ryou. Give up."
Gritting my teeth, I unleashed the stored magic in Muramasa, creating a powerful explosion between us.
Skidding back, I quickly checked for injuries. Aside from a few cuts from Muzan and scratches from Kokushibo, I was holding up. Kokushibo, however, looked completely unscathed. He extended his hand again.
"I'll say it one last time. Join us."
I sighed, settling into an iaido stance. 'One more time.' I poured all my bloodlust into Muramasa. 'Haven't done this since I fought Zeus, I think.'
I didn't fully understand how my attacks worked, nor the way of cursed magic actually worked. All I knew was that Muramasa's curse to drive me insane with ever-growing bloodlust functioned like a magic power similar to cursed magic. As I channeled the bloodlust, the aura around me faded, intensifying instead around Muramasa. Light seemed to warp, and the world around us began to lose color. I saw Kokushibo tense, his body readying itself for what was to come.
"It's useless, Ryou!" he shouted, blitzing towards me.
I smirked, pouring half of my remaining cursed magic into Muramasa, which intensified its aura. The entire area started to tremble. Ghostly screams echoed, haunting and fragmented, filling the space with the sounds of old and young alike. The aura surrounding Muramasa began to take on the shapes of people, as though struggling to escape the blade itself.
For the final touch, I gave Muramasa a bit more of my lifeforce. My body trembled slightly under the pressure, but I steadied myself as I looked Kokushibo dead in the eyes with a wide smile. I saw that he was slightly sweating now.
"I can't beat you? Who decided that?" I released the attack.
"Blood Oath: Cursed Severance"