Avataram Khatinam. Avatara Karyam Sulabham

The speciality of this avataram is that "Avataram Khatinam. Avatara Karyam Sulabham" whereas in all other avatarams, the Avatara Karyam was Khatinam while the avataram itself took place rather easily upon the Lord's Sankalpam.

Hiranyakashipu had obtained a boon from Brahma that he could not be killed either by day or by night, neither inside nor outside, neither in the earth nor in the sky, and no weapon could kill him. Additionally, his killer could not be any creation of Brahma or the any one among the trinity.

The Narasimhavataram was difficult because, the avataram itself could not be any creation of Brahma. By emerging from the pillar (Sthambam) in the form of Narasimha (half man-half lion), the Lord satisfied the condition of not being any creation of Brahma. Since he emerged at twilight (neither day nor night), the second condition was also satisfied. By carrying Hiranyakashipu to the doorstep (neither inside nor outside), the third condition was met. By placing Hiranyakashipu on his lap, Bhagavan Narasimha satisifed the condition of Brahma's boon that Hiranya could not be killed either on the earth or in the sky. Finally by using his finger-nails to tear Hiranyakashipu apart, Lord Narasimha upheld the last condition of Brahma's boon (no weapons could kill Hiranyakashipu).

Furthermore, the Lord had to remain in the pillar for a long time before incarnating. The Avatara Karyam was accomplished by Narasimha rather swiftly compared to those of the other Avatarams.