In such a perilous place, it was clearly not suitable to refine the Black Soul Flower. Even if others could not directly attack them, they could still cause disturbances through means such as falling rocks, as Martial Artists were most vulnerable to disruptions during cultivation.
Moreover, with the presence of the Soul-Extinguishing Cloud, a formidable weapon, it was best to leave quickly now that they had obtained the Black Soul Flower.
Three days had passed, and the Soul-Extinguishing Cloud had hunted again before returning to the sky, thus Chu Hao and his companions were able to leave the valley quite smoothly.
Red Flame Ridge had two other valleys where rare medicinal plants grew, but they did not visit them. One should be content. Moreover, they had already been delayed by so many days; it was possible that those Spiritual Medicines had already been harvested.