Physically, they cannot alter their form to create a seemingly more fair appearance to mortals, as Gods can do: they have to possess the bodies of other sentient beings to walk among them, and some Intelligences are incapable of even that. They also cannot, for the most part, see through the eyes of their worshippers as Gods can, nor do they possess the unique ability of Palladium Gods to create viable offspring with other lifeforms (in fact, Alien Intelligences cannot reproduce sexually with other species at all).