Karnasapatham (The Oath of Karna) is a famous Kathakali play focusing on Karna's emotional conflict when his mother Kunti reveals his true parentage before the Mahabharata war, urging him to join the Pandavas, a plea he ultimately refuses, leading to his tragic vow. It's known for its dramatic depth and is one of the most performed modern Kathakali works, featuring intense scenes of revelation and loyalty, available as music and performances.