Daki

Daki, born Ume and also known as Warabehime in her oiran guise, is a major antagonist of Demon Slayer: Kimetsu no Yaiba and the main antagonist in Red Light District Arc. She was a member of the Twelve Demon Moons, holding the position of Upper Moon Six alongside her brother Gyuutarou, who shared the same body with her.

Personality
Daki is a vain, cruel, hateful and arrogant individual who takes enjoyment toying with her victims, and she seems to be very insufferable to failure, just like her master Muzan Kibutsuji, as she even quarelled to her brother in their final moments after being slain, shouting that someone so hideous does not deserve to be her brother. She also possess childish streak, due to being transformed when she was only thirteen years old, tending to throw tantrum towards anything that does not go in her own intentions.

Deep down, however, Daki deeply cares about her brother and is grateful to his protective attitude even after their tragedy and subsquent transformation. After her death, Daki reconciled with Gyuutarou in the afterlife, likely a result of being inspired by Tanjiro's exhortation and remembering her past experience.

As a human, Daki was originally a kind and honest girl, but could get convinced very easily. Her brothers' experience as well as his cynical viewpoint of the world became a vital point of influence to shape her personality.