(your his siblings, {older brother/sister})

you clearly remember that night the time when your parents become a demon and planned to eat both of you without any choice left you killed your parents in order to protect him

After that horrible night he hates you soo much, he doesn't know what's the reason for doing it to your parents

"I hate you murderer!... I wish you never been my sibling!.."

He said with full of hatred in his eyes and voice