Lakshman, the avatar of Sheshnag......
Lakshman, the son of Sumitra, the younger brother of Ram, and the husband of Devi Urmila, is considered the incarnation of Sheshnag. Due to being the avatar of Sheshnag, Lakshman had a great deal of fervor. It was this fervor that made him unafraid to confront Lord Parashuram. When Kaikeyi decreed a 14-year exile for Ram, Lakshman, who had always been like a shadow to Ram since childhood, decided to accompany him.
Even as a child, Ram had said that Lakshman would always be with him, in his heart. Because of this bond, Ram could not refuse Lakshman's arguments and was compelled to take him along. However, Lakshman did not take his wife Urmila with him, as she had the responsibility of taking care of the family, which was essential for a daughter-in-law. Urmila, honoring her husband Lakshman’s wishes, fulfilled her wifely duties.
During the exile, Lakshman stayed awake day and night, serving and caring for Ram. To facilitate his service to Lord Ram, Lakshman received a boon from the goddess of sleep to stay awake throughout the exile. According to the Anand Ramayana, the sleep that Lakshman gave up was transferred to Urmila, who slept for 12 years. Due to this, Lakshman, who neither slept nor ate for 12 years, was able to defeat Meghnath.
Meghnath could not be killed by anyone else as he would always disappear in a magical mist. Lakshman had previously been defeated by him. According to the Valmiki Ramayana, Brahma had granted Ravan's son Meghnath several divine weapons and the ability to fly, with the boon that he could only be killed at the precise moment when he was offering oblations in the fire during a specific ritual at Nikumbhila. Vibhishan disclosed this secret to Lakshman, enabling him to kill Meghnath.
When Ram's mission on Earth was completed, it was time for him to return to Vaikunth (the divine abode). However, this was not possible with Lakshman around, as he could not leave Ram. The gods then entrusted this task to Sage Durvasa. Sage Durvasa requested a private meeting with Ram in his chamber, with the condition that anyone who interrupted would be sentenced to death by Ram. Ram appointed Lakshman as the guard to ensure no one entered. At that time, Kaldev (the god of time) arrived and insisted on meeting Ram, saying it was a matter of life and death. When Lakshman initially refused entry, Kaldev warned that it was urgent, forcing Lakshman to enter the chamber. Consequently, due to Ram's vow, Lakshman was sentenced to death. Following Hanuman's advice in the royal court, Ram decided to forsake Lakshman instead of sentencing him to death. However, to uphold his brother's vow, Lakshman took a jal samadhi (water burial) in the Sarayu river.