Pill Souls, as far as Alex understood, were pills that could be used twice instead of just once. The pill took its effects first, and then the Pill Soul was left behind, which then made its use at a later date.
That was the bare minimum of what Alex knew about them, mostly because Silvermist had never taught him about them at all. He had hoped for Alex to learn about it all by himself, and in doing so hopefully gain the Dao of Alchemy that no one had ever learned before.
As such, everything Alex learned about the Pill Souls was something he had learned through osmosis.
'A pill that can perform its effects twice,' Alex thought. 'I did just succeed in doing that, didn't I?'
