As per the Legends, A thief called Kalathushakan vowed that he would give half his ill-gotten wealth to Sri Vaikuntanathar. He was caught while robbing the place . He prayed to God for help. The Lord assumed the grab of the thief and taught philosophical truths to the King. The king, thinking that Kalathushakan was no thief but a Yogi, became his friend. As per the King's prayers, The lord assumed the name Kallabiran.
As per the Legends, a demon named Somakan stole the creative knowledge of Brahma. Brahma did penance here for the Lord Vishnu to recover the knowledge from the demon. Lord Vishnu fought with the demon and retrieved the creative expertise demon and restored it to Brahma.
As per the Legends, Kubera, the God of wealth, was cursed by Goddess Parvati because he was impolite and became bankrupt. Therefore, Parvati, in turn, lost all her Nava Nidhi's (nine forms of wealth) that were the Mahapadma (Sacred Lotus), Padma (Lotus), Shanku (Conch), Makara (Crocodile), Kachyapa (tortoise), Mukund (Quicksilver), Kund(jasmine), Neelam (sapphire), and Kharva(dwarf). These Nava Nidhis' did penance here for the Lord Vishnu to marry them. He responded and appeared as 'Vaithamanidhi' (one who kept the wealth safe), the protector of the Nidhis. Kubera relieved from the curse here.
The war between Dharma(righteousness) and Adharma (wickedness) took place at this spot. Dharma stayed here, praying to the Lord Vishnu. One day, Adharma attacked him and was sent fleeing by Dharma. Therefore. this area got the title Adharmapisunam.