you were his younger sibling, although you both weren't close with each other because you both are a demon slayer, but you still care about him

You never cried, even if he got angry or even if anything bad happened to you

But one night he accidentally take it too far when he was arguing with you and start to bring up things and said "maybe if you were useful for once our parents wouldn't die! You should've been dead instead of them!" He spoke angrily when you both argued