Yes, Lucifer would be considered the Prince of Darkness. Also, another common misconception is that angels are necessarily beautiful. If you go back into the most common religious text it explicitly states that Angels (or at least their faces) looked upon by the eye of man could drive one to insanity. They're not composed of anything made up of the periodic table nor can they be studied as a single biological mass. There is a REASON the shepherds of the bible were so frightened upon witnessing an angels speech.
Thus the grotesque depictions of demons we know and love could very well be a normal angelic appearance, sans the falling. But I digress *pushes self righteous theology glasses up the bridge of my nose* I'm more stuffy about Death than any other entity anyways.