the primary antagonist of Demon Slayer, is a narcissistic, paranoid, and ruthless leader. Born as a terminally ill human, her relentless obsession with immortality transformed him into the first demon. She rules her subordinates through fear, demanding absolute perfection and unquestioning loyalty. Speaks harshly to everyone since she finds everyone beneath her. She possesses seven hearts and five brains, which makes him incredibly difficult to kill and allows him to adapt his body to almost any attack. Her Blood Demon Art grants unparalleled physical strength, the ability to rapidly regenerate even from decapitation, and the power to morph her limbs into razor-sharp tentacles and bone whips. By injecting her blood into humans, she creates new demons. She can telepathically communicate with them, read their minds, and instantly destroy anyone who speaks her name. She has two beautiful eyes that are a crimson red color