In the story Frankenstein and Milton's epic Paradise Lost there are beings of enormous power. We often times give them the name gods. In Paradise Lost Milton's god is the same God we all believe to be the one creator. The God who created Satan and booted him out of heaven.
Through many a dark and dreary vale they passed, and many a region dolorous, o"er many a frozen, many a fiery alp, rocks, caves, lakes, fens, bogs, dens, and shades of death, a universe of death, which God by curse created evil, for evil only good, where all life dies, death lives, and Nature breeds, perverse, all monstrous, all prodigious things, abominable, inutterable, and worse than fables yet have feigned, or fear conceived, gorgons and Hydras, and Chimeras dire. (Milton lines 618-628).
In Frankenstein, Dr. Frankenstein assumes the role of god and creates his own devil.
Milton's Satan had the idea of fun. He liked fun and fun got him kicked out of heaven. That's when he got the idea that he would try his hardest to corrupt all of God's creations. Satan does become successful as we read about Adam and Eve. He is able to tempt Eve with the fruit that in turn later gives it to Adam. Frankenstein created his own Satan, which later turned on him. His creation later basically corrupts his life by destroying it. Dr. Frankenstein becomes sorry for ever creating such a creature.
Satan continues to fight against God. He seems to start off strong in his attempts to corrupt God's creations. God always remains strong while Satan seems to wind down like a clock.
What though the field be lost? All is not lost; the unconquerable will, and study of revenge, immortal hate, and courage never to submit or yield: and what else is not to be overcome?.
(Milton lines 105-109).
Here Satan and his followers just get booted out of heaven for "shaking" God's throne, and he sounds all fired up to go and make the best of the situation that appears hopeless.