looking for a movie or series... space/sci-fi

It's been driving me crazy that I can't find this movie or series. It had bodiless life forms / celestial beings that took over other planets and came to earth. There was a lady who was the main character and near the end she came out of a pyramid or some sort of portal. These beings were highly intelligent, they didn't eat or deficate and commented how the humans were an inferior race. They looked like a misty cloud or particles.