User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-63.117.245.61-20111010185107

The leviathans, so far, are not more evolved than the Archangels - who are essentially the perfect cosmic beings. They exist on the highest plane of existence. Hence being made out of light- energy beings.

The leviathans are just monsters. In fact they are probably inspired by the 1982 horror film The Thing starring Kurt Russell. That movie is an underappreciated masterpiece. Like The Thing, the leviathans are clever, can assimilate anyone by creating a perfect imitation, absorbing thier knowledge, and then eat the original.