The particles no longer stay behind when units move. I also removed the sparks that sprinkle down when the effect initially appears on a unit because I thought they were unnecessary, and as a result, only two custom textures are now required. Let me know what you think and if you want me to add them back.
There are two versions of the model with difference in how the large particles rotate after emission.
By the way, where did you find the model, if you don't mind me asking?