He is Rudra, he is Siva, he is Agni, he is all and the knower of all. He is Indra, he is Vayu, he is the twin Asvins and he is lightning.
स वै रुद्रः स च शिवः सोऽग्निः सर्वश्च सर्ववित्। स चेन्द्रश्चैव वायुश्च सोऽश्विनौ च स विद्युतः॥