From the Morphing Primitives participate a Square. You take that as a parent!!!!

Then you add a square rotated 90 degrees in the x axis. You set this up with a transparency of 1.1 - 1.2 or 1.3. Then duplicate it and set it "in front" in the z-axis 10 to 20 mouse clicks on the positioning wheel. Don't forget to assign it to the parent. I have no idea if it takes this setting with you when you duplicate it. So, you do that about 60 to 70 times. :)

Then you have the Fog-Cube a'la Jsenwark. You can then scale, rotate, etc. via the parent. By scaling you can influence the density of the cube. and of course by adjusting the transparency of the squares. it should always be above 1.1 the sqares don't need any color or texture, i just included them for illustration. Red for parent, blue for the "kids".

I can promise that the fog effects are just crazy. The denoiser even makes it look like billowing clouds. !! Look the last Godzilla pic.