"Normal human with wings" implies that he is an Incubus or a Nephilim. An Incubus is the male counterpart of the Succubus, which is the seductress demon. Nephilim are not bad in their own right, but their existence is debated. They're half-angel, half-human hybrids. They once lost favor with God through a revolt to seize the Earth, apparently (on the topic of Nephilim, Cassandra Clare's YA Mortal Instruments books are awesome). Lucifer was so incredibly prideful he saw himself greater than God. He attempted to conquer Heaven along with his fallen angels, but a legion of angels, led by St. Michael, the Archangel, quelled the rebellion, and Michael Chauvin-styled Satan, standing on his neck and "killing" him, banishing him to hell. I think the idea of several extra Archdemons including Lucifer and Beelzebub were pretty much added to make the bible a lot cooler. And add DnD opportunities. Which is perfectly fine and awesome.