Murugan is the physical form of Shiva. That is why He is the son meaning born of or created by Shiva, the term Shiva is such of description of Shi fire, Va, Vayu. This is reversed to Vashi in tantra which means Breath or prana. Prana means the creative power which is fire this element of Shiva is called Spirit in Latin which means breath and is called Fiery Ether this is because ether is vibration which is friction which is heat, light and consciousness this is what Shiva or Vashi means, Spiritual Fire. The tantra's state that the worship of Shiva is the fire of the inner Kundalini pranayama practices. The meaning of Shiva. In the West Dionysus who is Shiva was the Son of Zeus and the statement that Pan who born of his father the ether [Zeus] this is Dionysus who is born of Ether or Shiva also known as Spiritual fire. This is also the Japanese term Reiki.
A person who has transformed themselves into the light body is called The Son Of Shiva in the east. The term Shiva Rupa is the term for the Magnum Opus in the east. The form of Shiva. The Shiva Rupa is the perfected state brought about by the transformation of Spiritual Fire which is the element of transformation.
Murugan is the symbol of a person who has transformed themselves into Shiva the title of the ascended being the Shiva Rupa the form of Shiva is Shiva. By the energy of which is called Shiva. Satan is called these titles because He is also Sanat Kumara. And Sanat Kumara is the God of Kundalini Yoga in the east. He is on the level of what Shiva is as the concept of the incarnation of the form. An ascended master and He is also the physical being that is remembered as Shiva or Sanat Kumara when talking about the physical God as well for this reason. But this is also state in which one can ascend towards with the Magnum Opus or Shiva Rupa.