The Prince of Darkness himself, Lucifer is gentlemanly evil.  While fond of traditional visions of the Apocalypse, he's not terribly keen on the way things are going now, since it may mean not only the end of Heaven but also the end of Hell, and by extension, himself.  Since Lucifer's objective is to win the eventual war against Heaven, not to have it all end in a bloody draw, he's decided to take steps against the current situation.
Lucifer is a Seraphim, and despite rumors to the contrary he retained his angelic appearance when he fell.  Like Metatron, he has six wings.  His eyes are milky gold, and his hair is a mix of silver and blonde.  He has a fondness for wearing bows (because real men wear bows) and he carries around a cane topped with a carved snake's head clutching a ruby apple in its teeth.