Lucifer
NyarlathotepIn modern and late Medieval Christian thought, Lucifer is a fallen angel commonly associated with Satan, the embodiment of evil and enemy of God. Lucifer is generally considered, based on the influence of Christian literature and legend, to have been a highly regarded angel in heaven, prior to having been motivated by pride to rebel against God. When the rebellion failed, Lucifer was cast out of heaven, along with a third of the heavenly host, and came to reside in the world.
So both of them walk on Earth: one is the embodiment of evil and enemy of God, the other is the servant of Azathoth; one is the Biblical Devil, the other is the Lovecraftian 'Devil'. Both are looking to dominate all human being on Earth to serve their hideous purpose. Eventually, they start crossing sword with each other. Who'll win?Nyarlathotep, however, is active and frequently walks the Earth in the guise of a human being, usually a tall, slim, joyous man. Most of them have their own cults serving them, while Nyarlathotep seems to serve them and take care of their affairs in their absence. Most of them use strange alien languages, while Nyarlathotep uses human languages and can be mistaken for a human being. Finally, most of them are all powerful yet purposeless, yet Nyarlathotep seems to be deliberately deceptive and manipulative.