There are many ways you can do this...
One way is to use something that encumpasses the character like a sphere and add an animated texture to the sphere. Oh course the sphere will have to use a mask so that the parts of the texture that are not visiable hides the spheres geometry. I'm not yet that good with DB, maybe someone can give you a lil code.
Uhm another way to get an effect is to connect a particle emittor to your character and play with the settings to get what you want, and you will use one of your lighting textures that will need to have an alpha values so that the particles will blend, its the same as the mask on the sphere I mentioned, it hides the geometry and just shows the texure.
If I find any sold examples I'll post em.
G'day
IDIC (Infinite Diversity Infinite Combinations)