Most mythologies that circle around Shiva have subtle meanings in the science of Kundalini. The concept of Kundalini deals with Shiva in many ways. It is a school of thought that enables a human being to attain salvation through certain practices.
Its a belief that every human being has male and female energy within him/ herself. The female energy is typically referred to the kinetic energy and resides in the Muladhara chakra at the tip of the spinal chord. This element is represented as "Parvati" from the mythological perspective. The element of Shiva is the inactive energy which is housed in the region of the third eye. The merger of these two energies is defined as enlightenment which can be realized by individual experiences alone and cannot be explained.
As the female kinetic energy rises through the spinal chord upwards it has to pass through various energy centers called chakras. When the chakra at the throat region is activated, the aspirant is no longer dependent on the external world for his sustenance. The eternal drink of immortality or Soma/Amrit is believed to flow freely and the aspirant turns "immortal".
Soma Skanda in simpler terms, is the result of the union of these two potent opposite forces giving rebirth to the aspirant as an evolved being. This is best described in mythology as the union of Shiva and Parvati resulting in the birth of Soma Skanda and hence results in immortality.