Loki the Fire God

Ragnarok | Norse Mythology  (also Ragnarök, Ragnarökk)

Ragnarok, in Norse mythology, was the predestined death of the Germanic gods. A three-year winter led to a final battle on the Vigrid Plain, where the gods and the frost giants fought the epic final battle. Ragnarok marks the end of the old world, and the beginning of the new, current world.

Odin, who had previously attempted to prevent Ragnarok from occuring, led the gods. They were assisted by the heroic dead, those who had died in glorious battle and had been taken to live in Valhalla and await the final battle. The frost giants were led by the fire god Loki and assisted by the unworthy dead who came from Hel, and by other monsters.

Two humans, Lif and Lifthrasir, hid in a sacred tree called Yggdrasil during the battle and didn't return until after the battle. When they emerged, they repopulated the Earth. Other survivors of Ragnarok included some of the gods, particularly Odin's brother Honir, Odin's sons Vidar and Vali, Thor's sons Modi and Magni. Another of Odin's sons, Balder, was revived from the dead after the battle.

The Vikings were particularly interested in Ragnarok, and many of the Germanic peoples believed that the same type of battle would again occur. Even when Christianity began to take over their belief system, many of them still explored the idea of a Judgement Day in the same light as Ragnarok.

http://www.ancient-mythology.com/norse/ragnarok.php