The rain that finally overwhelmed the evil demon army was actually diluted Emperor's Liquid. Using the Heavenly Song to gather water vapor and create rain clouds, then mixing in the Emperor's Liquid. For demon beasts whose spirits had yet to awaken, this diluted Emperor's Liquid was still an invaluable treasure, significantly accelerating the demonization process.
It naturally could also grant a bit of strength to the Plant Demons under his command.
It must be emphasized again that only a nouveau riche like Wang Qi would use the Demon Clan Holy Medicine in such a manner.
"Now there are three enemies left, then there's one half-crippled, one mana-depleted and utterly exhausted... With the spirit energy environment so harsh, they wouldn't dare to absorb and refine it," Wang Qi reasoned. "So the remaining combat power lies with that Divine Tao Witch."
