Mahiravan kidnapping Sri Ram and Lakshman and Hanuman rescuing them is a famous story found in Puranas and local traditions. There are several versions of the story and Mahiravana is also known as Patalravana or Patal Ravan. In some versions it is Hanuman that kills Mahiravana and in some versions it is Sri Ram.
Mahiravana was one of the sons of Ravana and he did not take part in Ram-Ravan war in the Ramayana as he did not support Ravana kidnapping Sita. Mahiravana was a sorcerer and an ardent devotee of Goddess Kali.
To entice Mahiravana, Ravana gave the idea of sacrificing two brilliant young men like Sri Ram and Lakshman to Goddess Kali to gain unparalleled powers.
Mahiravana fell for this trap and kidnapped Sri Ram and Lakshman from the battlefield.
Hanuman went in search of the kidnapped Sri Ram and Lakshman and reaches the demon’s palace in the netherworld.
The palace is guarded by numerous forts and millions of soldiers and demons.
Hanuman defeats them all and reaches Sri Ram and Lakshman.
Mahiravana was getting ready to sacrifice Sri Ram and Lakshman to Goddess Kali. Hanuman then takes the form of a bee and whispers something in the ear of Sri Ram.
Sri Ram then asks Mahiravana to place is head on the sacrificial block.
Sri Ram says that as he is of royal lineage he does not know how to bow down and requests Mahiravana to show him how to do it.
When Mahiravana agrees and demonstrates it and places his head on the sacrificial block, immediately Hanuman takes his original form and chops the head of Mahiravana.
Another version
Hanuman goes in search of Sri Ram and Lakshman and ventures into the world of Patala Ravana each palace is guarded by demons. They try out numerous magic on Hanuman. He overcomes them all. He even fights Mahiravana but is unable to kill him.
Hanuman then meets a sister of Mahiravana who was imprisoned by the demon as a sorcerer had predicted that her son will replace him as the next king. Mahiravana never wanted to abdicate his throne.
The sister tells to Hanuman that Mahiravana’s life is hidden in three places – five lamps in the palace, in a diamond and in his heart. To kill him the three has to be destroyed at the same time.
Hanuman passes this message to Sri Ram. They hatch a plan. As per the plan Hanuman puts off the five lamps, Lakshman crushes the diamond and Sri Ram shoots an arrow into the heart of Mahiravana. All this take place at midnight when Mahiravana was about to sacrifice Sri Ram.
Mahiravana and Patalravana
These two demons are the same as both their stories have striking similarities. They are mentioned differently in regional versions. Mahiravana is mentioned as the son of Ravana. Patalravana is the friend of Ravana.
Patalravan did not have many magical powers as Mahiravana. In most stories it is Hanuman that kills Patalravana.