红颜薄命: Cursed Beauty (Yandere!KNY x F!Reader)

不死

Arc 3
不死 : Immorality

Tanjiro processes the information he received from Y/N's journal. He believes that he is an exception from the curse and is worried for the Ex-Phoenix Pillar who is surrounded by obsession.

Some time later, Muzan is searching for information on the Blue Spider Lily. During his search, he finds out that two of his subordinates have fallen at the same time Nezuko had conquered the sun. Suddenly feeling worried for the wellbeing of Y/N, he immediately returns home. Although he is relieved that she is safe, he still remains anxious, believing that the Demon Slayers are planning to take her away from him. Filled with impatience, the Demon King leaves for the Ubuyashiki Estate, not only to retrieve Nezuko but to also end the Demon Slayers in hopes to protect Y/N.

The Demon King and Ubuyashiki have their final talk before Ubuyashiki blows up his estate, setting forth their predetermined plan. Muzan heals slowly from the traps imbued in the explosion. During his slow regeneration, Tamayo appears and allows Muzan to absorb her arm that contains a cure. The Rock Pillar arrives and continually destroys Muzan's head. However, the growth of his head is too quick. While Muzan is immobilized, the rest of the Pillars appear. Just as they are about to launch their attack, they are transported into the Infinity Fortress.

While this is happening, the three Upper Moons are watching after Y/N. During their watch, Y/N is transported away and they are given the order to kill the slayers within the fortress. Taking advantage of the battles, Y/N decides to escape the Infinity Fortress. Amidst her search for an exit, she comes across Shinobu and Douma's battle. The Insect Pillar immediately attempts to give Y/N the cure. She receives the syringe but does not take it. Instead, she runs causing the two to chase after her.

As she runs, she comes across the Akaza vs Giyuu and Tanjiro Battle. Preoccupied with running from Shinobu and Douma, she ignores them and continues to run. Shinobu and Douma appear right after. The two chasing after Y/N causes the other three to join the chase, hoping to save Y/N from the hands of their enemies.

The pursuit is close, forcing Y/N to use her Demon Blood Art to inhibit them for a short while. Entering a different part of the Infinity Fortress, she meets Mitsuri and Obanai in their battle against Nakime. Yushiro enters the battle and takes over Nakime's vision.

No longer having to deal with the Upper Moon, the Love Pillar focuses her attention on Y/N. Mitsuri hands the cure to Y/N. At this point, the Phoenix Demon realizes that each of the Pillars have a cure. Still indecisive, Y/N once again, pockets the cure instead of taking it and immobilizes the Love Pillar. While the Snake Pillar is shocked by her betrayal, Y/N takes Obanai's stash of the cure before disappearing.

The Snake Pillar is unsatisfied by their short encounter and leaves to chase after her. Just as Obanai leaves to chase after the Phoenix Demon, the other five catch up. The Love Pillar recovers not long after and joins the pursuit.

Throughout her search for the exit, she comes across more and more slayers that abandon their fights to pursue her. In the end, she is unable to escape and is taken by Upper Moon One.

The other Upper Moons join them in protecting her from the demon slayers.

Because of the trauma she experienced throughout her life, Y/N is constantly looking for ways to become more powerful. This greatly affects her decision in staying a demon.

Using the cures she collected from the many demon slayers hoping to change her, she turned the three Upper Moons back into humans.

Now, the only one standing in her way of attaining true power was the Demon Progenitor himself, Muzan Kibutsuji.

Fortunately for Y/N, Muzan was only concerned with keeping her safe. When the battle was turning out for the worse, Muzan made the decision to transfer his power to Y/N.

Though this sacrifice was less than ideal, he believed that it would make Y/N stronger, increasing both their chances of survival. Especially since he noticed that the demon slayers were much less likely to do any harm to the former Phoenix Pillar.

Now, with Muzan's power, Y/N had reached the top of the food chain. Despite this, her weakness of the sun still remains. With the sun quickly rising and by the instructions of Muzan, Y/N attempted to consume Tanjiro in order to gain his family's sun immunity. However, she was unable to consume him in time.

Just when she thought she had failed, the demon slayers shielded her from the sun. This action shook the phoenix demon causing a chain reaction, resulting in the return of the memories she had forgotten.

Overwhelmed with new power and fresh memories, Y/N breaks down and seeks the comfort from the only one she could truly trust.

不死 directly translates to no death or Immortality . When the character 鳥 meaning bird is added, the word 不死鳥 then translates to Phoenix. This arc represents Y/N's internal conflict and whether she chooses mortality and immortality when presented the cure. During this Arc, when Y/N becomes a demon, she is closer to a true phoenix. Immortality is an important theme in this arc as it is revealed that Y/N's mindset mirrors Muzan's as her goal is complete immortality and invincibility. In the end, Y/N fuses with Muzan, reaching the pinnacle of power. Similar to the mythological phoenix, there can only be one phoenix alive at a time. After Muzan relinquishes his power by fusing with Y/N she becomes the one true immortal.