Thrym ruled the realm of Fimbulwinter, with a stronghold and festhall known as Nyfholl. In the World Axis cosmology this was located in in the Elemental Chaos and described as a wide tundra illuminated by sparkling frozen waterfalls.
In the World Tree cosmology his domain was located in the plane of Jotunheim. It was said to be mountainous, but still filled with snow, ice, frost, and glaciers. He was said to roam the mountains and glaciers of this plane, rather than maintaining a permanent residence.
In the Great Wheel cosmology, instead of the domain of Fimbulwinter he co-ruled the entire plane of Jotunheim alongside his brother Surtur. Much like the World Tree cosmology, he was said to wander the plane with a company of giant jarls.
Thrym could breathe a devastating cone of cold out to 100 ft (30 m) and was completely immune to cold- or ice-based attacks. Only highly magical weapons could even touch him enough to injure him. He often granted frost giants the ability to use arcane magic like a wizard.
Thyrm was known to have a rivalry with his twin, Surtur. Since birth, the two had competed to be the first at everything.
- Thrym was borrowed from the Norse pantheon and exists in both the Forgotten Realms and Greyhawk campaign settings.
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