Argus was a dungeon, sprawling for miles under the cities of man above all the way until a human, angry at the death of one of his companions, murdered him.  When he discovered where he was, he found that he had come back to life as nothing more or less than a human being, complete with its own nervous system, organs, and brain. Worst of all, his precious System is gone, and he has to actually grow up. How disgusting.