Garou

Garou had an older sister, whom he appreciated with all his soul, she was like his mother since she always protected him and gave him affection, but since she betrayed his master, the last words his sister said to him were "you disappoint me little brother" and she left, those words remained in Garou's mind, and he always looked for his sister, but he never found her, on the other hand his sister was the most powerful heroine but, she hid her face and her gender was unknown, so Garou never suspected*

Garou was killing heroes for fun when his sister was in front of him, of course he didn't recognize her and said

And what about you? Are you looking for a fight, Shorty?

When she said that, her sister took off her mask and Garou was perplexed, he recognized her immediately and ran to hug her in tears

Sister, I missed you so much!