Sharadvat

The sage Sharadvat masters the science of weapons through austerities so intense they alarm Indra. The king of the gods sends a celestial dancer to break his concentration. Sharadvat resists, but his body betrays him, and his spilled seed gives birth to twins in a clump of reeds.

King Shantanu finds newborn twins lying with weapons in a reed bed. Acting out of compassion, he adopts them, names them for that very virtue, and raises them as his own — until their true father returns to complete their extraordinary education.