After the great scourge Masefield was taken care of, he left behind a ball of light.
This was the primordial spirit essence.
Immortal cultivators in the Soul Splitting realm would leave a primordial spirit essence behind after their death.
This was because Masefield had eaten some kind of soul-like fruit and accidentally birthed a primordial spirit.
The primordial spirit essence contained a large amount of primordial spirit power.
However, Masefield was not an immortal cultivator. He did not cultivate any techniques related to the primordial spirit.
As a result, his primordial spirit did not contain much power. Still, it was important.
If an ordinary person were to absorb the power of the primordial spirit in this essence, their IQ would increase by several levels. At the very least, they would surpass great scientists like Einstein and Newton.