After I Died, I Became His Medicine Guide

I am a beggar who is born with a body that is invulnerable to all poisons. In order to have food to eat, Xie Jin made medicine. Su Niannian, daughter of Medicine King, junior sister Xie Jin. She killed me and used my blood to make an antidote for Xie Jin. Then he looked at me who had expired with contempt and said, "Does this little beggar deserve to be his wife?" My body was randomly thrown into a mass grave. And Xie Jin still wants to marry me.