Karna was given the Kavach and Kundalas at his birth for protection by his father, the Sun-god. The Kavach was embedded into his chest, making it impossible to hurt him with arrows. The Kundalas protected his ear’s cartilage from attacks. Together, they made Karna immortal as there was no other way to kill him. Indra, the chief of the gods and Arjun’s father, knew that Arjun would be in danger as long as Karna had his Kavach and Kundalas on. So, Indra decided to take them away and weaken Karna.
Lord Indra disguised as a poor Brahmin and approached Karna during his prayer time. The Sun-god warned Karna of Indra’s intentions but Karna did not want to send anyone from his door empty-handed. He readily gave away his Kavach and Kundalas to Indra, cutting them off his body. Indra was so ashamed that he gave Karna a boon to use his most powerful weapon only once during the battle.
Kunti went to meet Karna to reveal his true identity. However, he refused to join the Pandavas, saying, “I have already refused to Lord Krishna before. Anyway, it is too late to do that as I am a close friend of Duryodhan. However, I promise you that I will not kill any of the Pandavas except Arjun.”
On the tenth day of the war, the Pandavas could not keep up with Bhishma. Then, Krishna suggested, “Bhishma could lower his bow if a woman came before him.” As no woman was allowed in the battlefield, Krishna asked Arjun to keep Shikhandi in front of the chariot while fighting against Bhishma. Shikhandi was born as a woman but later became a man because of a demi-god.
Bhishma refused to fight against Shikhandi. Thus, Arjun shot a hundred arrows and pinned Bhishma down. There was no way to kill Bhishma as he had a gift of choosing the moment of his death.
Drona became the chief of the Kauravas’ army after Bhishma. He planned a war trap called Chakravyuha and made Jaidrath the leader of it. Only Arjun knew how to break this trap but Drona made sure that Arjun was nowhere near by.
As the Chakravyuha moved towards the Pandava army, it crushed them on its way. So, Arjun’s son, Abhimanyu, entered it but he did not know how to get out. He single-handedly fought against all the warriors. However, Duryodhan, Karna, Drona and Ashwatthama mercilessly killed brave Abhimanyu.
When Arjun heard this, he vowed to kill Jaidrath, the leader of the Chakravyuha. The next day, Arjun entered the Chakravyuha but was unable to reach Jaidrath until close to sunset. So, Lord Krishna created an illusion by which the sun set and the Kauravas stopped fighting against Arjun. “Arjun! Don’t lose this opportunity!” Lord Krishna shouted. When Arjun beheaded Jaidrath, Lord Krishna removed His illusion and the Kaurava army was surprised to see that the sun was still up.
Lord Krishna revealed a secret to the Pandavas to win against Drona. “Drona has vowed that he would stop fighting if his only son, Ashwatthama, was killed!” The following day, Bheem acted promptly according to Lord Krishna’s plan. He killed an elephant with the name Ashwatthama. Then, Yudhishthira informed Drona that Ashwatthama was dead without clarifying that it was not his son but an elephant. As soon as Drona dropped his weapons, Dhrishtadyumna (Draupadi’s brother) beheaded him.
On the other front of the battlefield, Bheem killed Dushasan to fulfil his vow for insulting Draupadi. Karna was the next commander-in-chief of the Kauravas’ army. Krishna advised Bheem to send for his half-demon son, Ghatotkach, for a surprise attack on the Kauravas. The magical powers of demons were said to be most effective at night. Ghatotkach played havoc with the Kauravas’ army and it seemed as if he would single-handedly destroy the whole army.
In desperation, Duryodhan asked Karna to stop Ghatotkach. Karna had to use the divine weapon given by Lord Indra and killed Ghatotkach. Seeing this, Bheem said angrily, “Krishna, my son is dead and you are laughing.” Lord Krishna said, “From the day this war started, I have been keeping Arjun away from Karna. I am laughing because Arjun is safe now.” Thus, Karna made himself vulnerable against Arjun.
When Karna soon stood face to face with Arjun, his charioteer was suddenly killed and one of the wheels of the chariot broke down. Karna requested, “Arjun, stop fighting while my wheel is fixed. I am unarmed and it is unethical to attack me.”
However, Lord Krishna said, “Karna, this war is unethical in itself. It will be foolish of Arjun not to take this opportunity to kill you.” Thus, Arjun killed Karna and the Kaurava army began to flee away from the battlefield. After Karna’s death, Duryodhan went missing and the Kaurava army surrendered.