In NARASIMHA Avatar, Lord Vishnu embodies himself as a semi-man, semi-lion in this world. The ruler of devils (asuras), Hiranyakasyapa, needed to get godlike and needed to stay youthful for eternity. 

To this end, he thought for Lord Brahma and due to his serious retribution, the divine beings were terrified and requested that Brahma mollify the ruler. Brahma was intrigued by his grimness and allowed him a desire. HiranyaKasyapa wanted that he be neither killed by a man or monster, nor in sunlight or around evening time and neither inside or outside a structure.

 Having gotten the desire he viewed himself as the incomparable God and frobade all love of divine beings by anybody. 

Yet, his child Prahlada, was a vigorous fan of Vishnu. This infuriated Hiranyakasyapa without question. He requested various approaches to execute Prahlada including asking his sister Holika to sit with Prahlada in the fire. However, everytime Prahlada got away from safe. 

Goaded, when he asked Prahlad to show him the Lord Vishnu. Prahlad stated, "He is all over the place". Further maddened, Hiranyakasyapa thumped down a column, and inquired as to whether Lord was available there.

 Master Vishnu at that point rose as a half lion, half man from the column which was neither inside the house nor outside, and the time was evening, neither night nor day. He at that point slaughtered Hiranyakasyapa consequently sparing the life of his fan Prahlada.