The spiritual beasts on the Path of Reincarnation and Cultivation need to take pills to evolve, but when feeding them, it depends on the experience value of the spirit beast. I can’t explain it clearly in just a few words. I suggest you read the article shared by the editor below to understand.
Alchemy, the first-grade Huanglong Pill, the third-grade Quchen Pill, and the fifth-grade Soul Purifying Pill
After the spirit beast's experience value is full, there will be an evolution key next to the experience value. Just feed the elixir there.
