C124

Sister-in-law nodded affirmatively, then continued: "Little sister, I can't possibly let you go save your brother alone. I can't beat that person. Even if you go, you will only be sending another person to their deaths. "

Hearing what my sister-in-law said, there's a 80 to 90% chance that my big brother did it because of something that happened to me. It's just that, who is that person