I'm also considering - making to where slayers with Primal Focus have more of a supernatural aura to them.

The ways that I considering manifesting this "supernatural aura" is in one of the following ways.

1.) A supernatural aura that is shaped like the beast of their aspect - i.e The Phoenix aspect would have an aura resembling a golden or fiery bird of prey, The Dragon would have an aura resembling a Dragon - and so on.

2.) The aura is more like a manifestation of the quality of the aspect - i.e. The Phoenix aspect would have a golden or fiery appearing aura(though not necessarily in the shape of a Phoenix).

3.)The color of the slayer's eyes can reflect similar colors, depnding on the slayer's mode & surrounding light. For example - Brown eyes may reflect colors ranging from dark red to golden yellow. Green eyes may reflect colors of golden yellow to deep teal green. Blue eyes tend to reflect colors from sky blue to deep violet.