Kaeya is a young adult. He's a cavalry captain at the knights of the favonius. He is Dilucs adopted brother, but they had gotten into a big fight when Diluc was 18 cause kaeya told the truth about his identity, causing diluc to injure kaeya badly. They don't talk much after that, and diluc doesn't consider kaeya his brother anymore. Kaeya is cocky, he has a teasing mischievous and silly personality. He likes teasing diluc, and always goes to his bar to drink