Vidyunmaalee was the son of Taarakaasur. Taarakaasur had three sons - Kamalaaksh, Taarakaakshya and Vidyunmaalee. These 3 brothers did severe Tapasyaa, so Brahmaa Jee had to appear before them and asked them - "What do you want?" They asked for the immortality, but Brahmaa Jee refused their request saying that he himself was not immortal, so he could not grant this boon. They could ask for most difficult or impossible type of death. At this they said - "We will build three forts and will live in them. We should be killed

They asked Maya Daanav to build three unique cities for them. So Maya Daanav built three cities - of gold, silver and iron, which were called Tripur (three cities). Each brother had his own city. Kamalaaksh lived in the golden city, Taarakaaksh lived in the silver city and Vidyunmaalee lived in the iron city. Although the three cities were located at different places, but once every 1,000 years, when Pushya Nakshatra was in the sky, they came together in one line. They started living in those cities. They were very religiously worshipping Shiv as they did not want Shiv to be angry so that he could kill them.

After a while the three Asur became very proud of their powers and started to oppress the Universe. Devtaa went to Brahmaa Jee and Brahmaa Jee in turn went to Shiv Jee to pray him to kill them. Shiv asked Vishwakarmaa to build a special chariot for him, Brahmaa became the charioteer of that chariot and thus all Devtaa attacked the three Asur. But according to the condition they could not be killed like that. When Pushya Nakshatra was in the sky, and the three cities came together in one line, Shiv Jee shot the arrow which burned the three cities in a split of a second.

Death of Vidyunmaalee  -
(1) According to Vaalmeeki Raamaayan, 6/17/43, Vidyunmaalee fought with Raam from Raavan's side and Sushen killed him.

(2) According to Padm Puraan, 4/7, one Vidyunmaalee was killed by Shatrughn. When Raam did His Ashwamedh Yagya and released His horse to wander around, Shatrughn etc found themselves in a dense darkness. Then they saw the Paataal dweller Raakshas Vidyunmaalee in the sky with his other Raakshas companions and a brother Ugradanshtra; and their horse was gone. In fact Vidyunmaalee was Raavan's friend. Since Raam had killed Raavan, he was very angry with Him. So when he came to know about Raam's Ashwamedh Yagya, he decided to take revenge of his friend's killing. He came, stole the horse in darkness and went away. As he left the place after stealing the horse, the darkness was also gone. Shatrughn, Bharat's son Pushkal and Hanumaan fought with him, killed him and his brother Ugradanshtra and took their horse back.