Fog cloud

i'd like to let a fog cloud fly around and shoot icicles to the ground. the icicles are no problem, the flying neither, but using a blended cloud model doesn't really look good.

anything behind or inside it should appear foggy, and the deeper the could is (from my viewpoint), the foggier the models behind it should be.

any ideas?

Why not use particles? There are some examples in Renanse Particle Editor that could very well look like fog.

looks good, suggestion accepted