Mephisto (Marvel)

Mephisto, sometimes using the name Mephistopheles or even Satan (among many others) is a powerful demonic super-villain from Marvel comics and is one of several such demons that feed off humanity's belief in the devil so as to masquerade as Satan himself. In reality however Mephisto's origin seems to lie with the primordial Elder-Gods that ruled earth before being banished by Attuma the God-Eater, the exact nature of this origin varies with story to story but tends to vary between the old gods becoming corrupt or the demons being formed by the already plentiful corruption found in the elder-gods.

At any rate Mephisto now rules over his own dark dimension, commonly called Hell but not related to the Biblical realm (though to the average human being it may as well be as it is equally as horrific), within this realm Mephisto rules supreme with only demons such as Blackheart (his own son) being capable of challenging him there.

Outside his realm however Mephisto becomes much more restrained, although still a virtually limitless sorcerer - he is aware of these limits and seeks ways to expand his influence throughout time/space but also, like many demons, enjoys causing misery and deception for no apparent reason other than malice.

Mephisto's main enemies are the Silver Surfer, Fantastic Four, Dr Strange and Ghost-Rider, Ghost-Rider is especially prominent since he was formed due to a pact with Mephisto but dedicated himself to stopping the devil rather than working as his servant.

Mephisto is also an enemy of Dr Doom due to the demon having trapped and tormented the soul of his mother, Cynthia Von Doom (note that this is only relevent to the comic canon and may or may not apply to other versions of Dr Doom).