Yun Qingluo had once told him that her blood was required to draw the attention of the particular crocodile. Also, she must be the one to take her blood sample. If others chose to take her blood forcibly, the blood would not work as bait for the Silver Ring Crocodile anymore. However, it was important to note that Yun Qingluo may not have told the entire truth.
Di Fuyi did not want to risk his life and venture into the unknown all because of her lies. In return, he made a few promises to Yun Qingluo in favor for her help. For example, when everything had been solved, he would let her go safely. She also requested that he not tell anyone about what happened to help her keep her dignity. If Di Fuyi chose to disagree, Yun Qingluo would rather die in agony than give out her blood to save her enemy's life.
