Proper Material Setup for PNGs used as Billboard-Like Effects

Hi all! I am currently designing a static scene in UE5 and was going to use some fog png’s so I wouldn’t have to use expensive volumetrics in my scene. What is the proper way to structure a png for use in a scene?

A few notes:

• Each png will be a material that will go on a plane so I can move it around a scene
• Each png material will need to react to light (i.e. lighter where light hits it and darker where it doesn’t)
• Each png material will need to cast shadows
• Each png material will NOT need to always face the camera like a billboard, although if that is possible that would be cool!

Thanks in advance!