Khsathra Vairya, Desirable Dominion, or Ksathra (Power), is third in the hierarchy, and would appear to be concerned with war since he protects metals, but according to the Bundahishn his role is the defender of the poor.
This is partially due because of the radical change which the role mythology of war underwent in Zoroastrian Persia (see Zoroastrianism); the role of warrior was reduced to protector of the unfortunate. If Khsathra military engaged it was to defend royalty, defend peace and promote religion.
Khshathra likewise is said to represent both the power which each person should rightfully exert for righteousness in the present life, and also the power of the kingdom of God.
He is the lord of the hard sky of stone, which arches protectively over the earth. His was the first festival, Maydhyoizaremaya, held in his honor and the creation of the sky.
Khshathra presented a problem to the scholar-priests because of his guardianship of both the sky of stone and men as warriors.
The problem really resided in his designation as protector of metals; with the emergence of the use of bronze, this no longer meant just stone but iron as well.
The priests’ ingenious solution evolved when they identified the stone of the sky as rock-crystal; a substance which they felt could be called a metal since it came out of the vein of rock.
Thus, to their satisfaction, Khshathra could still be venerated as lord of the crystal sky and protector of metals. A.G.H.
Boyce, Mary, Zoroastrians: Their Religious Beliefs and Practices, New York, Routledge, 2002, pp. 22, 33, 41
Grimal, Pierre, Larousse World Mythology, Secaucus, New Jersey, Chartwell Books, 1965, p. 190