Muzan

"Priestess. When I made you into a demon, I didn't think you would have such worthless blood demon art."

Muzan the demon king, glared at a shivering female demon. This female demon was wearing bloody priestess robes.

She was kneeling down before Muzan, trembling with fear.

"But my lord! My blood demon art is useful. I am not lying."

"I can see people's sins. And my purification flames can burn a sinner's soul."

The priestess demon spoke quickly, trying to prove that she was useful.

But the more she spoke, the more Muzan's rage increased.

"Is that why you thought to yourself, 'How ugly' when you met me today?"

"You are telling me that when you looked at me with those eyes, all you saw was sin?!"

Muzan's forehead throbbed. He was the demon king and thus could hear every demon's thoughts.

The first thing he heard was 'How ugly' when he met her today, after she awakened her blood demon art.

"What! You can hear my thoughts."

The priestess demon finally panicked. Looking at the angry Muzan, she believed her chances of survival were zero.

"No! You can't kill me. You really are full of sin; I am not lying!"

"You are in denial-"

*SPLAT*

Just then, the Priestess demon's head burst open, which killed her instantly.

"Trash."

Muzan growled, his eyes glowing red with rage. His eyes scanned the priestess demon's body, which was slowly turning into dust.

But there was something that didn't disappear quickly after her death. Her bright white hair, which looked like flames.

"Are those the purifying falmes? The flames, which are supposed to judge sins."

Muzan sneered and stomped the flaming hair angrily, putting out the fire.

*Wisss*

Or so he thought.

"Huh? Why did my feet catch on fire?!"

Muzan's eyes shook. The very next thing he knew was that his whole body had burst into flames.

"Aaaaaaaah!!"

Muzan screamed, the purification flames rose high, like they had found high-quality fuel.

The sins in Muzan's soul were so heavy that the dying flames had reignited.

"Aaaagh! Aaaaaaah!"

Muzan trashed around; this kind of pain had completely caught him off guard.

He felt like he was standing under the sun, but instead of his body, it was his soul that was burning.

"Aaaaagh! Noooo!"

Muzan kneeled over, and with a final, painful scream, the room felt silent. 

*Sizzle*

It only took a few more seconds before the raging white flames also disappeared. As if they had lost their fuel.

The only thing left in this room was Muzan's body, which was in perfect condition. 

Miraculously, the body had no burn marks on it. The only thing these purifying flames burned, was the sinner's soul.

Muzan, the demon king, was dead. 

Leaving behind his body as an empty husk.

*Twitch*

After half an hour, somehow Muzan's body twitched.

"Did I come to the world of demon slayers? Am I Muzan?"

Muzan, the demon king, was staring blankly at his hands.

It might seem like a miracle that a body without a soul has stood up again. But it wasn't a miracle.

"It looks like I became Muzan. This should be a parallel universe where Muzan dies abruptly."

Muzan got up and dusted himself up. This dust was the remains of the priestess demon.

Muzan looked calmly at the dust while remembering the original Muzan's memories.

"That priestess demon was once a human woman. Women like her are considered special."

"These types of women can suppress Muzan's curse on Ubuyashiki family, when they marry into that family."

"That's probably why her blood demon art was something like purification falmes."

"She was a special demon, just like Nezuko. Nezuko also had the sun flames as her blood demon art."

Muzan frowned. He should be careful before turning people into demons. 

The original Muzan randomly turned people into demons in the hopes of finding a special demon who could be immune to the sun.

"I am the demon king, but sunlight is my only weakness."

"I do not age; I do not die; I do not forget; I am immortal."

"I have seven hearts, five brains, a body tougher than steel, and I have no vital organs."

"But the moment I step into the sun, I will die."

Muzan shook his head. This was a terrible weakness to have; he needs to get rid of it.

He could understand the original Muzan's obsession. Everything he ever did was to find a flower called the blue spider lily. 

That flower was the answer to his problems; as long as he eats that flower, he will become immune to the sun.

"The original Muzan never found the flower, but I know where it is."

"Actually I don't need this flower. Nezuko and Tanjiro have eaten it already."

"Their blood contains the flower's extract, they have what I need. I just have to find them."

Muzan looked at his sharp and well-maintained nails. He was thinking of his next step.

"I won't go to Tanjiro's house. He remembered my scent in the original story; that gave me a lot of problems."

"I will send someone else to do this job. I will send a human to Tanjiro's house."

"Doma, demon rank 2 and the leader of Bliss, he is the perfect candidate."

"He has a lot of humans under his command. Those people can get Nezuko and Tanjiro's blood easily."

Muzan thought with narrowed eyes. Tanjiro was the last user of sun breathing and had a super sense of smell. 

He was a demon's natural enemy. Even if Tanjiro was weak right now, it was better for Muzan to stay away from him.

Why make Tanjiro a problem when he doesn't need to?

"Alright, will send human to Tanjiro's house then."

Muzan decided on a plan and immediately contacted Doma. His second-strongest subordinate.

"Doma, you need to do something for me."

Muzan telepathically contacted Doma and told him what he wanted. Muzan specifically told him to choose a good-natured human for this job.

Tanjiro can smell if someone is good or evil; it would be best if a good person approached him.

"I see Lord Muzan! I will get it done!"

Doma replied back in a sing-song voice, which seemed all too happy. 

But that was not true. Muzan could read Doma's mind; that guy had no emotions whatsoever. 

As a human, Doma was born emotionless; he faked having a smile all day long. And as a demon, he kept the same attitude he always had.

"I need better subordinates. None of them are loyal to me."

This was Muzan's only thought after he spoke with Doma.

"I have a lot of problems I have to deal with."

"Let me first become immune to the sun, then I will work on my subordinates."

"I need actual loyal subordinates, not idiots who follow me due to fear."

Muzan's future defeat was more or less because of his demons doing their own thing instead of fighting for Muzan.

Unlike the demon slayers, who were loyal to their lord, the demons under Muzan had their own individual agenda.

'If the demons truly turn loyal to me, demon slayers will stand no chance.'

"There is no way I will lose to them."