-Muspel is a realm of permanent warfare between the fire giants and the frost giants.
-The nature of Muspel depends entirely on whether the Frost Jarl or the Fire Jarl currently sits on the Throne of Muspel.
-Whichever side is currently losing is at a severe disadvantage, due to the hazards surrounding them matching their natural weaknesses. This means each side needs to find a clever/opportunistic way to stack the odds in their favor every time they become the underdog.
-Fire is mania, loud and furious. Frost is depression, quiet and cruel.
-Dragons of Muspel are in tune with their surroundings. Fire wyrms become frost wyrms when the Ice King takes the throne. They technically owe allegiance to whichever King sits on the throne, but only serve him when they believe it to be in their best interest.
-Both giant kingdoms enslave dwarfs, forcing them to serve as builders, miners and sappers.
-Slave revolts are especially common immediately after changes in season, since the jailers are suddenly at a huge disadvantage.
-Free dwarfs are those that have escaped and their descendants. The rooms and passages of their fortresses are too small for the giants to assault directly, but not for the younger dragons, who are rewarded with the largest shares of the dwarves’ hoards.
-After a successful raid on a dwarf fortress, the surviving dragons battle fiercely over the treasure they find. Only two or three at most usually survive this. These dragons often retire with their newly found hoards to isolated corners of the newly ruined fortress.
-Dwarfs build their fortresses near veins of precious minerals and gems whenever possible. Hoarding is in their nature, and mining is central to every dwarf culture that has ever formed. No one knows exactly why, including the dwarfs, who frankly couldn't care less.
-Gremlin spawning pits are natural features that produce fire gremlins or frost gremlins, depending on the season. Out-of-season gremlins establish a well-hidden spot to hibernate. The favorite activity of in-season gremlins is capturing and torturing dwarfs and their mortal cousins. Their elemental abilities affect metal objects, such as the weapons and armor of their victims.
-Wraiths are the spirits of those mortals who die in Muspel, and therefore cannot find their way to Elysium. Their powers and personalities reflect the state of Muspel at the time of their death. Their lairs are elaborate tombs that they build as shrines to themselves. They often have valuable information from their lives that they’re willing to trade for offerings.
-Wraiths can leave their tombs, but don’t often, because they are only at full power within their tomb. The tomb reflects the nature of the wraith; it’s always summer in a fire wraith’s tomb.
Like I said, I don't know which ones he's going with or how he's elaborating on (or completely subverting) them. Which ones do you weirdos like?