Jeramun
Jeramun, the Flame of the World is a powerful fire elemental from the plane of fire. After summoning him, the Aldar Dekalb created for him a great encasement of armour, both to protect the elemental fire and to protect the surrounding world from the immense heat emanating from his form. He also created a great sword for the elemental, but for what purpose we do not know. Perhaps he had foresight of the war to come, or perhaps he merely wanted his primitive companion to be protected.
When Dekalb was slain during the War of Humanity, Jeramun took refuge in a deep rent in the earth, for he could not abide the open air upon its surface. Despite his protective encasement, Jeramun radiated great waves of heat, and slowly his presence began to affect the very caverns around him, and the cold tundra far to the north was transformed into a sweltering, barren land, later named the Vents of Hthrak.