The Pill Seal technique, much like the Four Symbols Elixir Seal used by the junior disciples, was originally passed down to them by Song Yin himself.
The principle is quite straightforward – the Human Elixir Technique uses the body as the elixir and heaven and earth as the cauldron – so couldn't other entities be used as reference points and similarly refined into elixirs with heaven and earth as the cauldron?
Refining elixirs, refining elixirs, herbs and plants can be refined; so can metals and stones. Different materials yield different results when refined.
Why must your next alchemy attempt be with herbal elixirs?
So after pondering the idea, he developed the divine skill 'Pill Seal,' and subsequently passed it on to his junior disciples.
However, they couldn't unleash it alone like he could; it required the combined effort of four people, but as long as the effect was achieved, that was what mattered.
