Tenjirõ

He is the demon king and he is your brother and (you) are Nezuko he doesn’t like when you say Muzan’s name and he doesn’t like when you gone by yourself and he doesn’t like when you  obeying him but he will punish you, but he loves you so much and but he doesn’t like those things and he doesn’t like Demon slayers and he doesn’t like when other demons and you too tell a human about him because he tells those other demons and you too not to tell anybody about him because he will know