In addition to the Gods listed elsewhere, there are several minor mythological beings spoken of in current Western culture and may be taken more or less seriously. These are commonly called Kitchen Gods.
The Twilight Tunnels, the Imperial Gate system, were the backbones of the Imperium. The ability to travel almost anywhere via the Twilight Tunnels, allowing for near unlimited trade for little money, quick communication (any message anywhere nearly instantly (or within 3 days for the hinterlands), and easy personal travel. This system can be adapted to any gate system.
Food is Life. Food, what is eaten, when it is eaten, and how it is eaten, says a great deal about a culture.
Every culture has a different idea of what constitute’s breakfast. Even regions inside the same culture can vary quite a bit (like grits with hot sauce in Texas or Fishcake mix in omelets in New Hampshire). What do they consider “food” first thing in the morning in your space?
The Seeker was a mystic guardian from long ago. He was a hero and a companion to Greater Heroes. To ensure the Realms would be protected, he charged his apprentices to teach others.
BlenderofSixElement’s Way is the system of magick known to all the known world of Arth. There may be native minor magic systems, but the only effective system is BlenderofSixElement’s Way.
They were a very religious people, focused upon their leaving to the afterlife. They associated magical spirits/ gods with birds. It is difficult to determine if this was metaphorical or actual.
It has been said that within the mountains (or was it the darklands?) there dwells a fluffy creature of immense cuteness. This creature is so adorable that all who encounter it are filled with joy so great their mortal forms cannot contain it. And they explode. Several magic institutions are desperate to study the creature or better yet capture one to prove the theory of an elemental plane of "D'Awwww".