To perform Artifact Refining, fire is essential.
Mortal Artifacts use Mortal Fire.
Magical Artifacts,
naturally, must use Spirit Fire!
Dao Foundation Cultivators, with their Essence, Qi, and Spirit unified as one, can generate their own True Flame. This True Flame is omnipotent, capable of both Alchemy and Artifact Refining.
Innate Qi Refiners, however, do not possess such abilities.
They can only rely on external sources.
The Earth Evil True Flame is one such source.
Dragon Head Mountain, being a nexus of Heaven and Earth Primordial Qi, is connected to the Earth Veins below and channels a stream of Earth Evil True Flame.
"Senior Brother."
The disciple guarding the earth fire led Zhu Ju to a stone grotto, gesturing inside as he explained:
"The earth fire is ferocious and requires an Array to guide it for use. Operating the Array consumes Spirit Stones, so if you wish to use the Earth Evil True Flame, you must pay a fee."
