One of the twenty worlds – also known as “Terra”. Very little is known about this world, except that it was the origin of the Godslayer. The few people who have made the trek from Earth to the prime world have revealed a special form of magic (which they call “technology”) unlike any seen before.
Some have compared the Earthkin to the “Earthmasters” (who created the Godstones), but this comparison has no basis other than name similarity.