In the Gīta, Lord Krishna says to Arjuna that among the heroes Skanda shines as the generalissimo among warriors (senāni, i.e. Murukan). Those who want to be heroic warriors worship this form of Murukan. Chanakya in his Artha Śastra mentions the figure of Senāni on the ramparts of the Maurya kings.
Murukan was directed to be the Commander-in Chief by Śiva when the devas approached him with a request to conquer and eradicate Surapadma. So he is called Senādhipati' ('Generalissimo').
This image has six faces with twelve hands as per Kumāra Tantra. Of the six right hands, one is in the abhaya mudrā, while the others hold the thunderbolt, lotus flower, noose, club and mace. We can find the Senāni image in the temple of Peryianāyaki Amman in Devikāpuram, Tiruvannamali District.
From: In the Footsteps of Saint Arunagirinathar: Pilgrimage to the sacred places in the Tiruppukal by Valayapettai Ra. Krishnan