The main demon was calm, analytical and serene, gave advice to others and even suggested to his second body to calm down, which is why he was seen as the leader of the trio of demons. He was someone with logical thinking and proof of this is seen when he questioned Tanjiro's relationship with Nezuko, which he sees as abnormal due to the behavior of demons with humans, he is also someone who prematurely celebrated the victories by telling Tanjiro that he was a idiot for entering his swamp volunta