Sharabha , GandaBerunda, Pratyangira

STORY OF SHARABA( SHIVA INCARNATION), GANDA BERUNDAM(VISHNU FORM),

PRATYANGIRA( MAA DURGA FORM)

Narasimha -Sharabha Avatar of Lord Shiva.

The Narasimha-Sharabha legend is linked to gods assuming mythical animal forms to slay or subdue as the case may be. First, Vishnu assumed the form of Narasimha to slay Hiranyakashipu, an asura (demon) king, who was terrorizing the universe and devotee of Shiva. The Shiva Purana mentions: After slaying Hiranyakashipu, Narasimha’s wrath was not appeased. The world trembled, fearing what he might do. The Devas (the gods) requested Shiva to tackle Narasimha. Initially, Shiva brings forth Virabhadra, one of his terrifying forms, in order to calm Narasimha. When that failed, Shiva manifested as the human-lion-bird Sharabha. Shiva then assumed the Sharabha form. Sharabha then attacked Narasimha and seized him up until he was immobilized. He thus quelled Narasimha’s terrifying rage. Narasimha became a devotee of Shiva after being bound by Sharabha. Sharabha then decapitated and de-skinned Narasimha so Shiva could wear the hide and lion-head as a garment.The Linga Purana and Sharabha Upanishad also mention this mutilation and murder of Narasimha. After the mutilation, Vishnu assumed his normal form and retired to his abode, after duly praising Shiva. It was from here on that Shiva came to be known as "Sharabeshamurti" or "Simhagnamurti".

The Skanda Purana considers Narasimha as a mere irritation and not a threat to the world, contrary to what was brought out in the Shiva and Linga Puranas. The perception was that Vishnu may permanently adopt the fierce form of Narasimha, which would be detrimental to his role of doing good deeds. Hence, the purpose of Shiva assuming the form of Sharabha was to ensure that the lion body of Vishnu was discarded and he got united with his original divine form. Narasimha struck Sharabha with his body, it was Vishnu who groaned in pain and not Sharabha who was in an "adamantine body".

Shiva Purana describes the Sharabha for like this:

He had a thousand hands and wore matted locks. His head was adorned by the crested moon. He appeared like a bird with wings and beak. His body was fierce and fully developed.

His fangs were very sharp. Adamantine claws were His weapons. His neck was black in colour. He had huge arms and four legs. He was blazing like fire.

His voice was resonant and terrible like the rumbling sound of the clouds that gather at the end of the yuga. His three eyes were wide and blazing as the fire of the evil spirit of great fury.

His fangs and lips were clearly visible. He was producing a hissing sound of humkara. Shiva of such a form appeared in sight.

This fierce form of Shiva is also known as Sarabheswara.

It was then that Vishnu realised that Sharabha was none other than Shiva and bowed and praised Sharabha. Shiva then blesses Vishnu and gives him a boon to kill demons.[22] A Purana ends the story with gods fearing that Sharabha may not be able to control his rage and thus urging Shiva to give up his Sharabha form. Thereafter, Shiva dismembered Sharabha’s form; his limbs were given away and his torso became a Kapalika.

 The Vamana Purana too discusses the tale, ending with Narasimha becoming the calm Vishnu again and Sharabha becoming a lingam, the symbol of Shiva.

 One version also mentions that Sharabha after subduing Narasimha, assumed his original form of a lion, the mount of Durga, and returned to rest at the feet of Durga.

 In the Kalika Purana, Varaha - Vishnu’s boar avatar - had amorous dalliance with the earth goddess. He and his three boar sons then created mayhem in the world, which necessitated Shiva to take the form of Sharabha, to kill the Varaha form. Even, Vishnu requests Shiva to destroy Varaha, unable to control his own form. Here, Narasimha appears to aid Varaha. Sharabha kills Narasimha first and then kills Varaha, allowing Vishnu to reabsorb the energies of both his fierce forms. Finally, Vishnu defeats Sharabha.

After the Avatar or Sharabha - In some puranas says the narasimha swamy was more angered and took form of  GandaBerundam

 Ganda Berunda is described  as below.

GandaBerunda having two heads, fearful rows of teeth, black in complexion and with wide blazing wings. The destructive energy of Narasimha (Vishnu) in the form of the two-headed bird, began to fight fiercely with Sharabha (Shiva) for eighteen days. After the eighteenth day, Mother of all gods and trinity  form of 3 Godess Lakshmi Parvathi , Sarasvati - Godess Durga Devi took form of Maa Pratyangira  upon seeing maa prtyangira Lord vishnu  was finally able to overcome his infinite fierce energy, and regained control over it. In order to save the universe from Vishnu and Shiva's fiercest forms (Berunda and Sharabha), Vishnu stopped the fight, and Sharabha easily tore apart the two-headed bird. Narasimha (Vishnu) himself displayed now his peace, and Shiva finally transformed back in his usual form.

there are plenty Alternative endings from vyshnavites and shaivites

However, the motive of Lord Shiva as Sharaba was to pacify the ferocious Narasimha avatar of Lord Vishnu. Keeping this very motive as central, Sharaba succeeds in pacifying the Lion avatar, by subduing the energies of Vishnu which at that point of time were manifested as Narasimha and Berunda. The very purpose of Sharaba was to bring a sense of calm and well being to the three worlds which were frightened by Narasimha. In a sense, it takes to be even more powerful and superior to calm violent rage and anger.

Throughout Vedic literature there are many stories depicting Shiva resolving situations caused by Vishnu and similarly, instances where Lord Vishnu has taken superior forms to resolve situations of Lord Shiva. Shiva taking the Halahala soon after the great churning of the ocean and Vishnu taking the form of Mohini to end Bhasmasura, are some of them. The Vedas clearly state - Shivaya Vishnu Roopaya Shiva Roopaya Vishnave. The Smartha traditionalists and the Advaita school of thought go by that statement and accept both Vishnu and Shiva as equally powerful if not one and the same.
And it is believed that all the 3 gods are just different form  for doing different duties of the god. 

there are some different version of the same story
http://antaryamin.wordpress.com/2012/05/04/lord-narasimha-lord-sharabha-and-goddess-prathyangira/

But the final Intention was calm down 2 gods for the world peace.
Om Namah Shivaya, Om Namo Narayanah, Jaganmatha namo nama