On the day Murukan was born, Intiran became his enemy and tried to destroy him with his Vaccirayutam Halics (vajrayudha).
The six at once became one with six faces and twelve hands.
The devas each gave Him an instrument, separated from their bodies, to fight against 'Intiran':
He holds them in His twelve hands and appears majestic with them (Paripatal.5:55-70).
Vajrāyudha was given to Indra by Lalitāmbikā. Vajrāyudha is made of the spinal cord of a great sage Dadhīci, who was constantly meditation on Her.
Lalitāmbikā, in appreciation of his penance, took him with Her by offering him liberation through Vajreśī, a goddess on the banks of river Vajrā, whose darśan we had when we were in the open space between 11th and 12th forts.
The spinal cord of Dadhīci after his liberation was given to Indra as his weapon to destroy demons.
Vajrāyudha is considered as one of the most potent weapons. Kṛṣṇa talks about Indra on three occasions in Bhagavad Gītā (Chapter X).
He says, “I am Indra, among gods”; “Among elephants, I am Airāvata (Indra’s elephant vehicle)” and “Among thunderbolts, I am vajrāyudha.”
1) Indra has a powerful weapon called vajrāyudha (said to have been formed out of the bones of the Ṛṣi Dadhīca or Dadhīci), the thunder bolt.
This nāma (Vajriṇī, वज्रिणी, nāma 944) says that Lalitāmbikā holds vajrāyudha in Her hand to destroy the sinners.
The nāma could also mean that She is bedecked with diamonds and gems.
2) It is also said that Indra obtained his famous and the deadliest of his armouries called vajrāyudha after performing penance on Vajreśī.
She was pleased with Indra’s penance and gave him this armour and then only Indra could return to his world.
Vajrayudha (वज्रयुद्ध): The weapon with which Indra killed Visvarupa on suspicion because his mother belonged to the asura tribe of daityas