Legend of the Abyss
Arcane Magic was once the domain of the Elves of the Aelrretyn Empire. Legend says it was once the gift of The Old Ones to the Elven race. Since the Tearing, however, the god Ásvaldr cut elves off from Arcane use and gave it only to those who have the blood of Humans.
While now it’s use is mostly by humans, anyone who revives an Magic transfusion of human blood or has at least some human heritage may be able to use it. This transfusion is usually looked down upon as most of the time the process is not done willingly. There are exceptions, however, and humans have been known to on occasions form bonds with Elves feel are worthy to receive it.
Gnomes are the only other race other than humans that has innately has the use of Arcane magic. Some think this may be because of Gnomes origins, but Gnome blood transfusions have never been successful.
There are also several stand out blood lines in some Arcane users. These exhibit qualities of things that seem elemental to that of the Legendary Dragons of the Old Ones. Scholars think that these are strains of blood that have branched into “breeds” of sorts, though it is still debated in the halls of the Magi.