Karna Parva brings the war's long-building rivalry between Arjuna and Karna, Kunti's secretly abandoned first son and Duryodhana's most loyal friend, to its decisive climax, as Karna finally assumes command of the Kaurava forces after Drona's death. The battle between the two half-brothers, neither fully aware for most of the epic of their blood relation, unfolds as a contest between near-equal archers, until a series of misfortunes converge on Karna at once: his chariot wheel sinks into the battlefield mud, an old curse from a teacher who discovered Karna had lied about his caste to receive training strips him of a crucial weapon's knowledge at the critical moment, and as Karna climbs down to free the wheel, unarmed and pleading the customary rules against striking a defenseless combatant, Krishna urges Arjuna to fire anyway, reminding him of Karna's own presence during Draupadi's assembly-hall humiliation and his role in Abhimanyu's death, and Arjuna kills him. Kunti's earlier secret revelation to Karna, made shortly before the war, that he was in fact her son and the Pandavas' own eldest brother, adds a private, devastating layer of tragedy the other characters remain unaware of throughout the battle that kills him.