The foundational mantra of Emperor Gu's lineage was the Ancient Immortality Scripture. It deduced the secrets of immortality and the true meaning of life.
The Ancient Satanic Sect's most advanced collection was the Ancient Satanic Mantra, but they also had other mantras like the Ancient Satanic Avici Scripture which were related to the Ancient Satanic Mantra. Similarly, the Ancient Immortality Scripture also involved other branches of mantras, which included the Holy Lihuo Mantra. It allowed one to cultivate one of the Seven Legendary Primordial Fires, the Nanming Primordial Fire.
The Nanming Primordial Fire was very effective in battle. Another of its magical use involved the cultivation of pills. There was nothing like it.
Since Emperor Gu in the Antiquity Age, the Gu lineage controlled the Nanming Primordial Fire. This also enabled them to excel in pill cultivation.