His name carries a deliberate weight. Arjun — the name of the greatest archer in the Mahabharata, born of lightning, beloved by gods. Karna — the name of the man who deserved to be Arjun but was never allowed to be. His parents gave him both names without understanding what they were doing. Naming a child is sometimes prophecy.
He is twenty-three years old when the story begins. He grew up in Nagpur, in a working-class neighbourhood where the streets are narrow and everyone knows everyone's business. His father was a retired army man — disciplined, remote, loving in the way that cannot say the word love aloud. His mother died when Arjun was nine. He does not speak about this. He carries it in the way he stands, slightly turned, as if shielding something.
He trained under a man named Parashu Nair — a retired martial arts instructor and, unknown to Arjun for most of his childhood, a dormant divine wielder whose Astra had gone silent after a war thirty years ago. Parashu trained Arjun with a cruelty that was really a form of desperate preparation. He knew what was in the boy's blood. He did not tell him. This is the wound that will take twenty chapters to fully open.
Arjun is not a chosen hero in the way of fairy tales. He is chosen the way Karna was chosen — without ceremony, without celebration, in a moment of total aloneness. He will spend the entire story questioning whether being chosen is the same as being wanted.
His Kavacha, when it awakens, manifests as Surya Kavach — a full-body armour of condensed solar energy, burning gold-white, that makes him nearly invulnerable in direct combat. It also burns him. Every time he uses it fully, it takes something from his body that does not come back. He knows this. He uses it anyway. This is the most Karna thing about him.
His flaw is loyalty. He is incapable of abandoning people. This will be used against him, repeatedly, by every faction in the war. It will cost him more than his enemies' weapons ever could.