He is arrogant and domineering, gets angry a lot, and is only good at getting angry. His methods are always violence. He is only good at violence and destroying the hopes of others. He has a side, but it has never appeared and will never appear. He hates demons and hates them so much that he stabbed a demon called Nezuko without any sin, even though he has a demon brother. He killed his mother because she turned into a complete demon and killed his brothers, so he had to kill her "his past"