Most people forget that Lucifer is beautiful and make him ugly and demonic. He's a shapeshifter so he CAN look that way, but he was specifically created to be the point of perfection- that includes beauty.
How do you know he is beautifull? Some people really make a fool of themselves here. He in fact, and I am not talking about appearance, is ugly. Because he resembles the ugly side of our moral values. It's the reason why we kill, steal and lie. Romantisizing something that is in fact ugly is called fantasy, or escapism. Just don't get blinded by it. Have you ever been hurt by someone with a pretty face? The moment you do experience something similair, you will not so easily state that the Devil is a 'pretty boy.'