BACKGROUND
Lakshmana. The third child of King Dasharatha of Kosala and the younger brother of the great hero of Hindu mythology Rama. Also, according to some theories, all the four sons of King Dasharatha were born as personifications of Vishnu's might, so he too inherited a portion of that divinity.
In the Ramayana, he is described as the ideal younger brother, displaying unwavering loyalty and love towards Rama. When Rama was exiled from Kosala due the machinations of a political rival, Lakshmana followed him even though he had no obligation of doing so. Rama had complete faith in his younger brother as well, going as far entrusting him with the safety of his beloved wife Sita.
After Sita's abduction, Rama and Lakshmana endeavored together to rescue her from the Rakshasa King. Forging an alliance with the Vanara people, they invaded the Lanka Isle ruled by their bitter enemy. Lakshmana would then accomplish many military achievements in the issuing war. Worthy of special notice among those are the vanquishing of the Rakshasa princes Meghanada (Indrajit) and Atikaya.
Despite being a hero with such a brilliant legend (life), his end was too much tragical. And yet, as expected, that too was for the sake of his brother.
One day, after the period of exile expired and Rama returned to Kosala in order to inherit the throne, a certain saint visited the royal palace and asked for an audience with the new king. However, Rama was busy performing a private ceremony in honor to the gods at the time. In ancient India, to interrupt that kind of ceremony was a heavy sin, punishable by being cursed to death by the gods. On the other hand, to leave such an esteemed guest like a saint waiting was a serious breach of etiquette, which could leave an unremovable stain on Rama's honor.
Naturally, without any hesitation, Lakshmana decided to take the fall for his brother. He informed Rama about the saint's arrival and guided him to see the visitor. Then, with his role fulfilled, he silently took his last breath.
Regret of a Lifetime
We are repeating ourselves here, but Lakshmana acted as an ideal younger brother towards Rama. He always demonstrated unwavering loyalty and love towards his brother, though times of joy and adversity alike. While he was also capable of teasing and jesting at Rama occasionally, his commitment to his brother could not be questioned.
But even such Lakshmana still had a disagreement with Rama once.
After the end of his exile, Rama returned to Kosala and was crowned king. However, upon learning of the circumstances behind the conflict with Ravana, the people of Kosala began to doubt that Sita was capable of preserving her purity while a captive of the Rakshasa King and refused to accept her as their queen. In order to fulfill his duties as a king, Rama had no choice but to divorce Sita and send her away from Kosala.
Lakshmana could not accept that. After everything they went through in order to rescue her, it was wrong for Rama to abandon his wife now. Regardless of the circumstances, he had to stay by Sita's side to the very end. Otherwise, all would turn into lies.
But Lakshmana's wishes would not come to pass. Sita was forsaken as an immoral woman. Rama spent the rest of his days as a lonely king.
Being unable to accept such outcome, Lakshmana has answered to the call of the Holy Grail. His wish could not be any other: the reconciliation of Rama and Sita. This time for sure, he will break the abominated curse that keeps the couple apart and lead them to a happy ending. He has to. After all, it was his fault the two were separated in the first place.
...once upon a time, there was a she-devil who attempted to seduce Rama. Outraged by her insolence, Lakshmana violently sent her away. Feeling humiliated, the she-devil went to her brother for help and asked him to avenge the insult.
The she-devil's name was Shurpanakha.
Her brother was Ravana, the Rakshasa King.
Lakshmana’s rash actions were the final trigger that sealed their fates together with demon lord's.