After both the idols were consecrated, the power of Lord Vishnu spread throughout the village. Hearing this, the asuras became again furious. They sent one of them to destroy those idols. He went in the form of a holy Brahmin. During those days, Brahmins in the temple were fed twice a day. This asura also joined them. During the daytime, he remained like a normal Brahmin, but during night time, he changed his form. After that, he began to eat the cows donated to the temple and threw their bones northwards. Thus, the place came to be known as 'moorikkunnu' (moori means cattle and kunnu means hill in Malayalam). He also ate some sleeping Brahmins. But no one knew the real killer, as there is no any carnivorous creature nearby. People thought it is any ghost who is eating the cows. Finally, the 11th day (Ekadasi) in the dark fortnight of the month of Kumbham (February-March) arrived. The asura considered that time the most suitable to fulfill his task. One midnight, after all poojas were completed and everybody slept, the asura entered the sreekovil by destroying the pillars. At that time, Lord Vishnu appeared from one of the pillar in the form of Narasimha, his fourth avatar, and killed the asura in the same manner he killed Hiranyakashipu. After hearing the thundering sound made by the asura, all people woke up and rushed to see what happened. After seeing the ferocious form of the Lord, many people fainted. Some people prostrated on the ground and chanted the names of the Lord. They did not have the courage to look upon the ferocious form of the Lord. At that time, sage Amalaka came there and chanted the names of the Lord. After that, the Lord came back to his original form, and blessed his devotees. To prevent from further attacks, some power of Lord Shiva was also disposed in the idol, thus a concept of Lord Shankaranarayana also appeared. Even on special days associated with Lord Shiva, like Mahashivaratri, Pradosha vrata and Mondays, many people visit Thiruvilwamala Temple.