Shadow Walkers is a term that I sort of came up myself to descirbe this particular type of otherkin. Shadow Walkers are of a different nature then the Lycan, or Vampires, and other simillar otherkin that involve the spirit and qualities of another being residing within the mortal body. A Shadow Walker might be more commonly known as a Grey as some like to call them.
And what a Grey or Shadow Walker is, is one whom as an inherently neutral, they do not choose either the Right Hand or Left Hand Path but walk directly down the middle of it.
Which is part of why I have come to call them Shadow Walkers, because they are not of the dark or the light, but between the two. Shadow Walkers tend to be gifted in the use of both "dark" and "light" energy and are capable and willing to use any form of magick in any given situation. They see and understand the need for the balance, both darkness and light, and the balance lives within them.
Greys often tend to be quite misunderstood by others, becasue they do not see things in crisp Black and White, or Good and Evil, they understand the concept of these thigns but for them, the world is made all in shades, and is not so simple and cut and dry as a lot of people like to make it. A Shadow Walker, can see the vice in the rightous and the virtue in the unrightous.
They also tend to have a strong sense of morals and vaules, as well as truth and justice, becasue they are not prejudice of one side or the other, so they can see the full picture of a thing and view it from all sides. Though thier sense of ethics, might sometimes not be the same as others or be understood by others.