By the blood of the ancient gods. According to the questioning novel This Fairy is Too Serious, Wu Luan's strange disease was cured with the blood of ancient immortals. While looking for a cure for strange diseases, Wu Luan happened to find that his blood could inspire the power of ancient gods, so he came to the remains of ancient gods, got the blood of ancient gods from the artifacts of Yi people, and cured his strange diseases in the ceremony.