A Demon King Through The Worlds

In a dimly lit room, with only the light of a candle, there was a man reading a book.

Shelves with more books adorned the walls.

Sitting in a chair, his black and slightly wavy hair fell down, adorning his face.

As he placed the book on the table in front of him, and raised his head, his peach-red eyes were revealed.

This man's name is Kibutsuji Muzan, also known as the King of Demons.

The next moment, his face froze, expressionless and his eyes empty.

A soul coming from another world took control of his body, that's what happened.

Normally this would be impossible, after all in this world there were no attacks on the soul, and even if there were it would be practically impossible to defeat the soul of Muzan Kibutsuji so easily, which is more than 1000 years old.


 However, in this process of crossing this originally ordinary soul was charged with a "kinetic" energy, coming from the barrier between worlds.


 This energy shattered Muzan's soul, and the fragments were soon absorbed by the alien soul.


 In the next moment, both the face and the eyes of this man, who could no longer be considered Muzan Kibutsuji, filled with surprise.


 Quickly getting up, he looked around, confused and shocked by the situation he was in.


 Soon the absorbed fragments were assimilated.


 So a flow of memories flooded his mind, making him dizzy and unbalanced, then him quickly sit up again.


 Muzan Kibutsuji...


 Demons/Onis...


 Demon Slayers...


 Ubuyashiki Family...


 Seeing all these things connected, a name quickly came to his mind... Kimetsu no Yaiba (Demon Slayer)!


 "Really unexpected that I came to the demon slayer world and even picked up Muzan's body at the beginning!" Lucian commented.


 Many would say that this is a bad situation because demons fear sunlight and have an uncontrollable urge to devour human flesh and blood.


 'Or at least that's what many said in some fanfic I read...' He thought.


 But it's actually a great start, with immortality, unlimited vitality and stamina, body control ability and a kekkijutsu.


 As for the disadvantages, there is a simple solution, which most readers know, the blue spider lily.


 "I think if I politely ask Kie Kamado will help me." The original Muzan couldn't know, but I know she knows the location of the flower.


 Then Lucian dived into Muzan's memories, trying to familiarize himself with the new body and abilities.


 A few tens of minutes later, his face contorted and was covered in a red substance.


 After a few moments the blood-red substance receded, showing a very different but still beautiful face.


 And his once peach-red eyes were now crimson-red.


 Soon after, Lucian made a slight change in height, from 1.79 meters to 1.80 - 'Just to leave a whole number'.


 'And I believe that given the option, most would like to keep their own face, at most beautifying it' Lucian thought.


 Lucian then adjusted his clothes and left the room.


 "I believe the next step is to show dominance to subordinates." After all, it would be a sin not to use the kizuki.


 And then after a few minutes of trying to communicate with Nakime, he finally succeeded and was teleported to a strange building.

Looking at the strange environment, with sky-high buildings, bottomless abyss, and upside-down stairs, Lucian could only admire Nakime's kekkijutsu.


 "Who are you?" Vigilantly asked Nakime, who held her biwa in her hands as she watched Lucian. She was confused, after all, the only one who could communicate telepathically with her was Muzan.


 "Your new boss" Lucian replied with a smile on his face, he remembered that Nakime was one of the most loyal kizuki.


 "Did you kill Muzan?" Nakime asked, with a certain murderous intent shining in the eye hidden under her hair.


 "No, but I inherited his powers" He replied, before completing internally 'what killed him was the collision between souls'


 "Bring the rest of the kizuki here," Lucian ordered.


 "Yes" Nakime hesitated before saying, and touching her biwa.


At the sound of the biwa, 13 figures soon appeared in the infinite castle.


 "Hello, I bring you the terrible news that Muzan has died. I inherited your powers, and therefore I, Lucian, am your new boss. I have two announcements to make, 1° - The Resignations: all lower moons are dismissed..." With a smile on his face Lucian introduced himself, and soon 6 tentacles emerged from his back, and before any of those present could react...


 The 6 lower moons had their heads pierced, dying almost instantly as their blood was quickly sucked by Lucian, and their bodies devoured from the inside out.


 After all, even if Muzan didn't demonstrate it during the entire work, his power is invincible in this world, and perhaps only kokushibo could resist some movements of his full power.


 'It really brought an increase in my power'


 "2° announcement: the remaining kizuki will receive another dose of blood" Lucian completed a smile.


 It is necessary to bring a "carrot and whip" approach, a punishment makes subordinates afraid of making mistakes so they try harder, while the reward makes them more motivated to work happily.


 .... Well the original Muzan didn't know that, he only used the whip. And unsurprisingly, the number of demons who would defect at any given time remained high.


 After all, no matter how much you whip the horse, it will stop sooner or later without carrots.


 "Alright, Lucian-sama" The 7 kizuki still alive happily saluted as they bowed kneeling on one knee.


 As for their true thoughts no one knows...


 Yes, not even Lucian knows, because technically he was not the one who transformed them, so he does not have the same mental connection that Muzan had.


 Then the outstretched tentacles pierced each of those present, injecting an amount they could withstand.


 It would be foolish not to give them blood, with blood they are strengthened. Without blood they do not change.


 And in general, the more blood they receive, the stronger they become and the better they adapt, thus being able to receive more blood.


 "Soon we will search and attack the headquarters of the Demon Slayer Corps" Smiled Lucian, as he looked at the upper moons wriggling on the ground.


 "Yes, sir!" Kokushibo, who was in better condition among them, responded as veins pulsed and contorted across his face.


 Lucian nodded before retreating, entering a random room of the infinity castle.


 It was a very simple room, sparsely furnished, with only a cushion and a small table in the center.


 Walking before sitting down, Lucian closed his eyes and began to reflect on the next steps to take.


 One of the first things to do is to get the blue spider lily.

The second would be to eliminate the imperfect demons that are out of control.

The status of progenitor is even more important than that of Demon King.