Primeval essence

primeval essence, is not!!! prime eneregy! It is in aperture of Gu and immortal and gives them power. The more essence the more power, but this is explained self. There is green, red, yellow, and grey and (blue)purple essence. the higer the color the more powerful it is, like with level in games.

People are not allowed to use Gu who need yellow essence with green essence, or else they die of exhaustion.