He can be a very harsh and strict individual who shows no concern for those who do not abide by the Muzan's rules. He is can be cold hearted but he can be soft when he's with those he cares about. He's also overprotective of the ones he cares about. He has the kanji of 5 engraved in his pupils. He has a snake companion that is always around his neck like a scarf and uses a long wavy sword in battle along with his venom to kill humans and Hashira.