Srutayudha
Śrutāyudha (Devanagari: श्रुतायुध) was the Kshatriya (warrior) king of Kalinga (Odisha) .He was the son of water deity Varuna and his wife Parnasa. Kalinga is mentioned to have joined the Kaurava camp in the epic war. Srutayudha's mother had wished for a boon from Varuna for his son so that he could not be slayed by anyone in battle. Varuna had presented a magical mace to Srutayudha by using which he would stay undefeated in battle. He is mentioned in Drona Parva or in a chapter in the text Mahabharata. Varuna had also warned about the adverse effects  of the magical Mace if it was used against an unarmed opponent. According to the warning, the Mace would strike back Srutyudha himself if he used it against any unarmed person. Srutyudha stood in the front of the Akshauhini of soldiers in the Kaurava side along with Sakuni, Salya, Jayadratha, two princes of Avanti named Vinda and Anuvinda, and the Kekaya brothers, and Sudakshina the ruler of the Kamvojas, Jayatsena, Vrihadvala, Kritavarman . The Mahabharata describes these selected warriors as the tigers in men. On the first day of the war, he confronts Arjuna’s son Iravan and gives him a  good fight but is defeated by Iravan. The Mace Used in the Battle by Srutayudha. As per the narration in the epic of Mahbharata, Srutayudha challenged Arjuna in the battlefield while he marched on his chariot into the lines of the Kamboja army division and targeted Kritavarman. Srutayudha stuck Arjuna and Krishna with multiple arrows and injured them in the height of the battle. Arjuna fired back arrows at him and then cut off Srutayudha's bow and then his quiver and then struck him on the chest. Arjuna then killed Srutayudha's steeds and charioteer incapacitating his movement on  the chariot in the battle. Srutayudha filled with wrath rushed at Arjuna with his magical mace and hurled the mace at Krishna who was an unarmed participant in the battle as the charioteer of Arjuna. As per the conditions described by Varuna earlier while gifting the Mace to him, it didn't harm the unarmed Krishna but boomeranged back on Srutyudha killing him.