Abhimanyu is a brave, legendary and tragic warrior from the ancient Hindu epic Mahabharata. He was born to the third Pandava prince Arjuna and Yadava princess Subhadra, who was also Krishna's sister. As an unborn child in his mother's womb, Abhimanyu learnt the knowledge of entering the deadly and virtually impenetrable Chakravyuha from Arjuna. The epic explains that he overheard Arjuna talking about this with his mother from the womb. Arjuna spoke about entering Chakravyuha and later Subhadra dozed to asleep. Upon seeing Subhadra asleep Arjuna stopped explaining and did not proceed with explaining the way to escape the Chakravyuha. As an effect, the baby Abhimanyu in the womb did not get a chance to get complete knowledge about the Chakravyuha.

Abhimanyu grew up into a brave and gallant warrior since he was the grandson of Lord Indra, the deity of enchanted weapons and battles. Due to his extraordinary deeds, Abhimanyu was regarded as equivalent to his father and was capable of containing legendary warriors like Drona, Karna, Duryodhana, and Dushasana.

The Kauravas challenged the Pandavas to dismantle the Chakravyuha, a circular battle formation, on the thirteenth day of combat. The ‘Chakravyuh’ in Mahabharat was an excellent formation made up of a large number of soldiers standing together in a spiral shape, which became harder to conquer as a person reached the inner layers.

It was the best example for the Hindi quote:

“Jo dikhta hai wo hota nhi aur jo hota hai wo dikhta nhi!” (What appears to be, isn’t always the truth and what is true isn’t always clearly visible!)

The Pandavas agreed to the challenge because Krishna and Arjuna already knew how to take down such a group. But that day, the Samsaptakas forced Krishna and Arjuna into a conflict on a different front. The young man Abhimanyu, who knew how to get into the formation but had no idea how to get out of it, was their only option since the Pandavas had already agreed to take on the challenge. The remaining Pandava brothers resolved that they and their allies would also enter the formation with Abhimanyu and help the youngster escape it in order to make sure that he did not become imprisoned in this endeavour.

Abhimanyu successfully entered the formation by using his understanding of the Chakravyuha. The Pandava brothers and allies tried to follow him inside the formation, but Jayadratha, the Sindhu king, effectively blocked them off by using a Shiva boon to keep off all the Pandavas except Arjuna for a day. Against the entire Kaurava army, Abhimanyu was left on his own.

Abhimanyu caused massive destruction to the Kaurava army. He defeated Dronacharya, Kripacharya, Drona's son Ashwatthama, the eldest of Kauravas Duryodhana, King Salya, Duryodhana's brother Dussasana, Bhurisrava. Duryodhana’s son Lakshmana and many other warriors were killed by this lone warrior who came in blazing like a thunderbolt.

Duryodhana was furious after seeing his beloved son die and gave the command for the entire Kaurava force to kill Abhimanyu through any and all means. Following Dronacharya's suggestion, Karna destroyed Abhimanyu's bow by shooting arrows from behind him after repeatedly failing to pierce his armour. Soon after, his chariot broke, the charioteer and the horses were killed, and all of his weaponry were destroyed. He then made an effort to beat off the bow-wielding warriors on horses and elephants while shielding himself with a chariot wheel. Abhimanyu and Dushasana's son fought viciously with their hands. The Kauravas joined him in battle while breaking all military regulations. He fought back until his sword snapped and the last chariot wheel disintegrated. Shortly after, Dushasana's son used a mace to shatter Abhimanyu's skull, killing him. But before passing away, Abhimanyu killed him with his own mace.

When Abhimanyu was killed, it led Arjuna to believe that this was a battle—or rather, a war—that he MUST win. In war, the outcome is more important than morality, which the Kauravas had abandoned. when they killed the righteous Abhimanyu, a 16-year-old boy. The Kauravas violated the morals and norms of war that were expected of all warriors by murdering Abhimanyu covertly and in the most terrible way. The Pandavas had now dropped their guard, and Arjuna resolved to ensure Jayadratha's awful demise. Arjuna was so horrified by the terrible killing of his son Abhimanyu that he killed Jayadratha with his divine arrow out of wrath. Abhimanyu's death served as a catalyst and turning point in the conflict, swinging the balance in favour of the Pandavas, as Lord Shri Krishna had anticipated from the beginning.

It is also believed that Abhimanyu was actually the Moon God Chandra's son- Varchas reincarnated. Since Lord Vishnu wanted him to be born on Earth in the Kuru bloodline as he had a significant role to play in Mahabharat and in particular the Kurukshetra war - Chandra allowed him a 16-year-sojourn on Earth. Whatever the mission, it had to be wrapped up in 16 years of his life because that is all the duration his father could bear to be separated from him, and hence the early demise of the warrior.