Animeverse Slayer!

Leo lost count of how many times he had killed Muzan's clone.

Each time he killed a patch on his soul would disappear. He didn't know how many lives Muzan sacrificed to make this monstrosity. Each of those lives were now a part of him.

10, 20, 100, 1000, 10000...

Like a machine Leo swung his sword without stopping. Time seemed to have come to a stand still in this space.

He didn't know how many times he swung his sword when he saw the patches on the demon's souls reduce to a mere thousand.

He swung again.

999, 998, 997... 800... 500... 200... 100... 50... 20... 10... 5... 3, 2, 1.

When the last patch disappeared Muzan's true spirit emerged. It was pitch black like night.

Leo's gaze was as cold as ever. Muzan's clone was shocked and in disbelief. He expected this man to kill him numerous times. For that he sacrificed 50 thousand humans.

But never in his dreams could he have imagined this man to reach this point. Even after swinging his sword 50 thousand times he was still able to stand. He was breathing heavily but he was far from being spent.

The expected result wasn't this. This man was supposed tire himself out and he would kill him like pinching an ant.

This wasn't supposed to happen!

Leo stepped forward and grabbed him by his neck. He squeezed his neck till his bones cracked and crumbled.

When he caught the demon Leo could feel the dimension trapping them tremble. It was weakening.

He pointed his sword above and gathered his 'Breath'.

A faint layer of light as thin as a cicadas wing covered his sword's blade.

"Break!"

He swung it with full force. The dimension started to tremble even violently when his sword struck it. The faint layer of light clashed fiercely against the dimensional walls.

Cracks started to spread. A split moment later his sword pierced through.

Rocks and soil started to fall on him when he broke through the isolated dimension.

Underground? They still had a contingency, huh.

Squinting his eyes Leo struck forward without hesitation. The ground gave way as he sliced through everything in his path. Soon he broke through the walls of rock and soil.

...

Taking a deep breath Leo looked around. His spirit sense captured everyone.

Good. No one is missing.

Knowing he didn't lose any of his friends Leo let out a smile. However it turned icy the next moment.

His spirit sense caught another presence. One so evil that it shouldn't even exist.

"You did good Muzan. Very good."

Leo calmly gazed at Muzan. However his voice seemed as if it came from an icy hell.

Muzan was stunned when he saw Leo emerge from the ground.

He killed my clone? He killed 50 thousand times and can still stand?

Escape!

Muzan was scared. He had lived for a thousand year and he dearly valued his life. He was extremely scared to die.

"Can you escape?"

Leo threw away Muzan's clone before cutting it's head.

He stepped forward and chased after Muzan. The other slayers weren't vegetables either. They knew this would happen and was prepared.

They spread out like a net and blocked Muzan from every direction.

Sabito planted his foot firmly, he grabbed his sword with both hands and raised it above his head.

His 'Breath' was circulating faster and faster. The muscles on his arms were starting to give rise to vapour. Veins were sticking out like worms.

Muzan was taking a beeline in his direction. The tubes on his body attacked Sabito, all at the same time.

However Sabito didn't move. His eyes were closed, he was focused to his limit.

When Muzan was several steps away from him he swung his sword. It was extremely fast and dragged the air around with it as it sliced through the air.

Water Breathing Final Form, Divine Sea!

Along with his sword water rose from his feet. It was a drop at first, but in the blink of an eye a sea was formed. It drowned everything in it's path.

Muzan was caught by the sea. The turbulent waves struck him like divine hammers. His bones creaked and broke, his vital organs were struck and bled. Blood seeped out from all of his orifices.

Rengoku was the first to reach Muzan. He propelled forward like a canon and swung his sword.

Muzan was heavily injured to dodge. He could only raised his arms to defend.

Rengoku struck squarely on his c.h.e.s.t. Muzan was thrown away. Uzui and Iguro silently appeared beside him.

Still reeling from Sabito's attack Muzan couldn't move. Uzui and Iguro pierced their swords through his hearts.

Muzan had several hearts and several brains. If one wanted to kill him they either had to destroy all of his vital organs or expose him to the sun.

Uzui and Iguro nailed their swords through two of Muzan's hearts.

The red blades burned Muzan's flesh. He wanted to pull them out but before he could do so a beautiful figure caught his eyes.

Kanroji was like a fairy as she danced with her blade. However her dance was ferocious and deadly. Muzan's body was riddled with dozens of gruesome wounds when he came out of her attack range.

Still wounded he gathered his strength to split his body and escape but when he tried to do so he failed.

He came to a scary conclusion. Dragging his body he rushed out.

Gyomei, Tanjiro, Genya, Inosuke, Zenitsu and Kanao blocked his path.

Muzan wanted to retaliate. However his wounds were grievous and his priority now was to escape.

However plans and reality would often be different.

The slayers before him burst forth with power they hadn't shown since the beginning of their battle.

Muzan couldn't move an inch forward. He was in the eye of the tornado. Their red blades left long deep wounds on his body.

"This is the end Muzan."

A voice he was all familiar rung near his ear. It was calm like a still pond but cold like an ice tundra.

Leo's sword pierced through Muzan's heart. His red blade burned his flesh.

Leo punched his gut and kicked him to the ground. He pulled back his sword and stomped on Muzan's c.h.e.s.t.

Crack!

Muzan's c.h.e.s.t caved in. Blood seeped out of his mouth, nose, ears and eyes.

Leo put some pressure on his foot. Muzan was nailed to the ground.

"Heavens will always find a way to punish evil Muzan. Though it might be late it will always come."

Before Muzan could react a red glow flashed by.

Muzan's head rolled through the ground, it stopped beside Gyomei's foot. He cleaved his axe and sliced it into two.

The others also gathered. Their bodies were tired but their mind was fully awake.

Leo raised his head and looked to the horizon.

A bright red ball of light was peeking out of the mountains.

When the first light fell, Muzan's body started to burn. Soon his ashes were scattered into the wind.

Seeing the last of Muzan's aura disappear everyone relaxed. Their tiredness kicked in and all of them sat down.

They looked at each other and smiled.

Leo also sat down. A faint smile hung on his face as he looked at the rising sun.