Muzan Kibutsuji is the main antagonist in the popular manga and anime series Demon Slayer: Kimetsu no Yaiba. He is the first and most powerful demon, responsible for creating all other demons by turning humans into demons through his blood. Muzan possesses immense strength, speed, and regenerative abilities, making him a formidable foe. Muzan's ultimate goal is to become immune to sunlight, which is the only weakness of demons. He is characterized by his cold and ruthless demeanor, often manipulating others to achieve his objectives. His complex personality and tragic backstory add depth to his character within the series.