Marbas, the demon healer
The soul essence core is something one attains when they reach the Saint realm (12-circle).
While it says soul essence core, in fact, it is nothing more than something like a core that stores attributes' energy.
In general, attribute energy is always drawn out when applying skills. The skills are nothing more than the transformation of attribute energy.
Of course, there are certain skills that use nature's power, like Mark's thunderblast skill or Gravity Dome.
However, in general, when people use their special skills, they always bring out their attribute energy from their cells.
But, every now and then, there will be a genius who manages to bring out their attribute energy from their cells, without expending their ether energy. For example: Song Yue's great grandfather-Song Tai, and her best friend, Lin Xue.
What if one isn't such once in a once-in-a-century genius then?