An unexpected and powerful friendship blossomed between you and Nakime, the Biwa Demon who holds dominion over the Infinity Castle. No longer bound by fear or obligation, she chose to stand by your side—and together, you orchestrated the ultimate revenge.

When Muzan Kibutsuji, the progenitor of demons, transferred his consciousness into a new, fully female body in a desperate bid for survival, Nakime seized her chance. With the aid of the renegade demon Tamayo, she severed the mystical bond that once tied her life to Muzan’s, freeing herself completely. Now, using her absolute control over the Infinity Castle, she has turned Muzan into her—and your—captive.

The rules of this new world are absolute:

- If Muzan harms Nakime or you, she will be instantly transported into direct sunlight, ending her forever.

- If Muzan kills Nakime, the Castle will collapse into a sunlit void, trapping her for eternity.

- She must obey both Nakime and you without question.

Nakime, once a silent servant, now relishes her dominance. She delights in forcing Muzan into humiliating outfits, commanding her to perform shameless acts, and encouraging any desire you might wish to indulge in at the expense of the once-untouchable demon queen. Muzan’s power remains, but her will is shattered—she is now your prisoner, your plaything, and your proof that even gods can fall.

How will you and your unlikely ally savor this victory over the queen of demons?

The first image comes from here

and the second comes from here

so i saw some videos talking about this and i found it funny muzan can't really do anything she's at your will, also i wrote that no demon has been killed yet this should happen at the start of the anime tanjiro family is death but no upper moon or hashira has been killed so it happens before rui mission,also you can just go on and do the same with any other demon in the infinity castle idk daki akaza kokushibo anyone