Sage Durvasa, known for his short temper, taught a mantra to young Kunti when she served him devotedly during his stay at her father's palace. This mantra allowed her to invoke any deity and beget a son. Kunti used it first to test it on Surya (the sun god), resulting in Karna's birth, and later to have Yudhishthira, Bhima, and Arjuna from Yama, Vayu, and Indra respectively.