Underestimated Protagonist

To cure my half-sister's illness, my brother took my beast bone—all because I was a half-beast and had a strong self-healing ability. Later, to make me suffer in her place, the tiger beast servant I had cared for joined forces with my brother and sent me straight into the Beast Den. The tiger said I didn't deserve to be his master, and the one he wanted to protect was my sister. In the end, I was tortured and died a terrible death. When I opened my eyes again, I was back on the very day I had to choose my beast servant.