The following story about Hariharaputra has been translated from Mahasaasta Puranam
Hariharaputra (the son of Vishnu and Shiva was born to slay a Rakshasa King Kalikeyan. The story given here traces the birth of Kalikeyan, birth of Hariharaputra, Marriage of Hariharaputra, War between Kalikeyan and Hariharaputra and the final victory of Hariharaputra)
Birth of Kalikeyan
Once upon a time, the land around the foothills of Himalayas was ruled by Rakshasa kings - Sthulakarnan and his brother Sumukan. Sthulakarnan was very cruel by nature and a cannibal, who derived a lot of pleasure in eating Brahmins and sages who lived in and around the Himalayas. Sthulakarnan's wife, Sugandini, was very pious and kind. She was an ardent devotee of Lord Shiva. In due course, Sthulakarnan's wife conceived.
Once Sthulakarnan went on a hunting expedition and came across a group of young children who were playing in the field. Sthulakarnan could not resist the temptation of wanting to eat those children. He kidnapped one of the children who was playing and thought to himself that instead of him eating the child, if he could coerce his wife to eat this child, it would make his child in the womb stronger. However his wife refused and to the contrary requested him to let the child free.
In the meanwhile, the kidnapped child's father who was a sage got to know of his son's plight through his intuition and came to the palace of King Sthulakarnan. On reaching the palace of King Sthulakarnan, the sage requested him to let go of his child. As the king refused to let the child go, the sage, holding a handful of sacred ash, prayed to Lord Shiva to kill Sthulakarnan and set his child free. The sage then blew the sacred ash towards Sthulakarnan. The sacred ash transformed itself into an arrow and cut Sthulakarnan's head. The saint's child was released and they left to their home.
Sthulakarnan's brother, Sumukan, then took over the responsibility of ruling the kingdom. In due course, Sugandini, Sthulakarnan's wife gave birth to a beautiful baby boy. He was named Kalikeyan.
Kalikeyan learns about his father's death
Kalikeyan grew up to be a brave lad. When he was of age to rule the kingdom, he got to know about the details of his father's death. Angered by the fact that the saint through his magic killed his father and these saint's were protected by the Demi-gods, Kalikeyan vowed to strengthen himself and vanquish the saint's and the demi-gods. To achieve this end, Kalikeyan went to the forest for penance.
Rakshasas take help from King Ugraveeryan in the absence of their King Kalikeyan
At this time, the North western part of India was being ruled by a rakshasa King Ugraveeryan. There was a popular temple devoted to Goddess Kali in his kingdom. Once while on a hunting expedition, Ugraveeryan came close to the temple of Goddess Kali and wished to visit the temple. Once he reached the temple, he discovered that a Magician from south of India, through the use of magic, was trying to forcefully take the Goddess to his palace, much against her wish. Ugraveeryan got extremely angry and fought with the magician and won the battle with the magician.
According to the advice of Goddess Kali, Ugraveeryan spared the life of the magician, but broke his teeth so that he would never be able to chant the mantras properly and cut his arms to avoid him from doing any pooja.
Pleased with the valour of the King, Goddess Kali blessed the king with such valour and success that no other king in heaven or earth will be able to win over him and only a son born to Lord Shiva will be able to vanquish him.
The central part of India was ruled by the King Vijayakesari, who during his hunting expedition used to come towards Kalikeyan's (since Kalikeyan was on penance) land and apart from killing the animals used to kill the rakshasas who lived in the forests. Annoyed by being picked everytime by King Vijayakesari, the rakshasas of Kalikeyan's country approached King Ugraveeryan and sought his help to fight Vijayakesari. King Ugraveeryan fought with King Vijayakesari, killed him and won the battle.
Kalikeyan returns from the penance
In the meanwhile the rakshasa king Kalikeyan was very firm in his penance and the creator Lord Brahma appeared before Kalikeyan and granted him a boon. Kalikeyan asked for success over all the worlds and death only by a son born to Lord Shiva and Lord Vishnu. Brahma granted his wish. Kalikeyan returned to his kingdom. Once Kalikeyan returned, he heard about all the help extended to his people by King Ugraveeryan and they became friends. King Kalikeyan appointed King Ugraveeryan as the Commander to his army to fight the Devas.
Kalikeyan fights the Gods
Bouyed by the boon granted by Lord Brahma, King Kalikeyan fought a battle with the Devas and won over the Devas. Then, King Kalikeyan came to the abode of Lord Brahma and sought his blessings. Then he went to Vaikuntam, the abode of Lord Vishnu. Kalikeyan fought with Lord Vishnu. However, as Kalikeyan had a boon, he won over Lord Vishnu. Lord Vishnu, then gave him a lot of wealth as war tax and sent Kalikeyan.
Kalikeyan then came to Mount Kailash the abode of Lord Shiva and sought his blessings, after which he returned to his country. Once back to his country, Kalikeyan started to torture the sages and their guardians in heaven - the Devas. Some of the sages who escaped the clutches of King Kalikeyan, came to a place called Tharukavanam, where many other sages were living.
Few sages escape Kalikeyan's torture
These sages discovered that the sages living in Tharukavanam, had come to the conclusion that pain and pleasure are the direct results of one's own action in this as well as previous lives and the Gods cannot do anything about it and hence all prayers were futile. Their philosophy of life spread throughout the world. Because of this mistaken notion, the world reeled under a lot of misery.
Saddened by the developments, the sages who came to Tharukavanam, approached Lord Vishnu and prayed that he personally get involved and set things right. Lord Vishnu suggested that all of them approach Lord Shiva to find a solution.
Sages pray to the Gods to vanquish evil in the world
At the same time, all the devas, unable to bear the torture of King Kalikeyan, under the leadership of Lord Indira approached Lord Brahma and sought a solution to their problems. Lord Brahma suggested that all of them approach Lord Shiva to find an end to King Kalikeyan's rule. The sages with Lord Vishnu and the devas with Lord Brahma approached Lord Shiva with their problems and sought the intervention of Lord Shiva to set things right.
Lord Shiva suggests a way out
Lord Shiva told Lord Vishnu to take the form of Mohini and go to the sages residing in Tharukavanam, while he will go as a Bhikshadana (a nude beggar). As per directions of Lord Shiva, Lord Vishnu went to Tharukavanam in the form of Mohini, the divine enchantress. The sages in Tharukavanam, were so enamoured by Mohini that they started to follow her.
Lord Shiva in the form of a Bhikshadana approached the wives of these sages who were arrogant in the thought that there were no other women on earth who were as devoted to their husbands as them. However, the moment they saw Lord Shiva in the form of a Bhikshadana, they were so lustful that they started to follow him without even noticing that the dress they were wearing had slipped and fallen to the ground. Lord Shiva slowly made his way to where Lord Vishnu was in the form of Mohini.
When Lord Shiva reached the place where the sages were, the sages realized that their wives were enamoured by this Bhikshadana (little realizing that this was Lord Shiva himself). In anger all of them teamed up together and performed a black magic ritual from which came a Tiger, an Axe, a Deer, a snake, the deity of death and disease. The sages commanded each of these to attack Lord Shiva in the form of Bhikshadana. Lord Shiva killed the tiger, skinned it and wore the skin around his hips like a skirt. He held the axe and the deer in his hand, wore the snake as his necklace and pushed the deity of death and disease at his feet and danced over him. The sages finally called upon Lord Agni the deity of fire and got a drum from him which they commanded to attack Lord Shiva. Lord Shiva took the drum in his hands. Having been unsuccessful in all their attempts, the sages were confused.
Lord Shiva then took his original form and told the sages that he played this whole drama to make them realize their mistake and that he was not angry with them.
Birth and childhood of Hariharaputra
Lord Vishnu in the form of Mohini wanted to see Lord Shiva in the form of Bhikshadana once again and fell in love with Lord Shiva. Out of their union was born a child - Sri Hariharaputra (Hari = Vishnu; Hara = Shiva; Putra = Son).
While the child Hariharaputra was growing up, Lord Shiva wished to have a place made for him and called for the architect of the Devas to construct a beautiful city for his son. As per directions from Lord Shiva, the architect constructed a beautiful city called Tejovathi. Lord Shiva then appointed Hariharaputra as the ruler of the whole universe (and hence the name Saasta or Mahasaasta) and commanded the four Vedas to take the form of an elephant and become Mahasaasta's vehicle.
To be continued...