Some time ago, I needed a purple aura and since I didn't saw anything similar anywere, I made one myself. Now I'm uploading it, it might be of use to someone.
It's a pulsing purple glow that comes from under the unit, it can be used as an aura or anything else.
One question, which could be used to put it as part of the "sky" on a map? bone could be placed as a sun, but the sun instead put your model, so that it looks like a planet from another world.