Vertical rainbow ointment

Qin Bai Sheng announces a group of rare black spirit antelopes for auction, with a lowest price of ten immortal essence stones, and notes that the price can be lowered if vertical rainbow ointment is used to trade. The Gu Immortal selling that beast group requires a Gu refinement material, vertical rainbow ointment, so bidding may use immortal essence stones or vertical rainbow ointment. ^{ch. 750}