Answer by Raakhee Venugopal:
Thank you for the A2A.
I would like to share this story of Panchajanya here:
As per Harivamsa, Krishna, the avatar of Vishnu, is described possessing a shankha called Panchajanya, one of his four attributes together with the mace Kaumodaki, the disc-like weapon Sudarshana Chakra and a lotus flower. The conch was used during the Kurukshetra War. Panchajanya or Shankhasur was an evil sea demon who lived in a colossal conch shell in the deepest depths of the Prabhasa ocean or was a demon in the form of a conch shell. He kidnapped the son of Sandipani, the guru of Shri Krishna, Balarama and Sudama, and imprisoned him in the conch shell. Upon completion of their studies, Krishna, Balarama, and Sudama persuaded the teacher to ask for the preceptor’s dakshina (fees) of his liking. Sandipani asked for, as his dakshina, the restoration of his child. Krishna became enraged when he heard about the kidnap and plunged into the sea to rescue the son of Sandipani. Krishna successfully slew Shankhasur and took the conch shell for himself.
He then named the conch shell after the Demon. Whenever Krishna blows from the shell it foreshadows the death of his next opponent.
And this story about Arjuna’s Devadatta shankh…
Devadatta (also known as Varuna Shankha) was a gift to Arjuna from Varuna. This was a heavenly gift. When Arjuna prayed to the heaven gods in between his exile, He got gifts from them, which were immensely powerful. He got his powerful bow “Gandiva” from Indra and the conch shell from Varuna.
Indra had promised Arjuna to give all his weapons sensing an impending war with the Kauravas, but on the condition that he would receive the Pashupatastra from Lord Shiva. Following the advice of sage Vyasa to go on a meditation or “tapasya” to attain this divine weapon, Arjuna left his brothers for a penance. Arjuna travelled for a while before reaching the mountain Indrakila. Here he sat in meditation in the name of Lord Shiva. Shiva appeared soon enough in the guise of a hunter. Shiva challenged Arjuna for a fight and although he defeated Arjuna, Shiva was very pleased with bravery and prowess of the prince. Consequently, Shiva transformed himself to show his real avatar and blessed Arjuna with the Pashupatastra. Other Devas like Kubera, Yama, Varuna and Indra followed suit and blessed each of their potent weapons to Arjuna.