Taste my craft

Two days later, they went around the foot of the mountain and climbed up the Thousand Medicines Mountain. Feng Jiu followed at her mother's side, watching her skillfully explore the path in the forest, checking whether any ferocious beasts were around and paying attention whether guardian spirit beasts would appear when they were gathering herbs.

For two days, they did not encounter any major events or dangers. They walked to the edge, close to the precipice, where the first herb seemed to grow.

She looked at her mother who was squatting down to pick a spirit herb and asked, "Martial Uncle Shangguan, Martial Uncle Duan and others said you must gather three kinds of spirit herbs. What kind of spirit herbs are those?"

She was curious, which three spirit herbs must be gathered? What's more, it seemed that if all the three herbs were taken and handed to Master Third Sun, there's a good possibility that her mother would die. Why?