Mephistopheles

Mephistopheles, (ex) servant of Lucifer, father of Purvis and Payne.
 
Mercurial, slippery sycophant who often has unreadable motivations.
First appeared in Season 2. Last seen thrown into The Abyss of Pandora's Box- his fate remains unknown.
Season 2
When Fionn Corvin first travelled to Hell, to reclaim Stick's soul from Satan and see his father's old domain, he soon came across Mephistopheles. Waiting at the tree beyond the gate of Limbo with two Nightmares, he introduced himself as Lucifer's trusted servant and was, by extension, at Fionn's disposal.
Acting as a guide he lead Fionn through the nine circles of Hell, giving a running commentary on the geography and poltics of the damned realm. When Fionn, Leviathan and Proserpine launched the overthrow of Satan, Mammon and Asmodeus, he stood on the sidelines. A servant, not a revolutionary.
Fionn Corvin never successfully figured out whether he could trust Mephistopheles or not.
Season 3
When Ford made a fantastic voyage into the Belph's subconcious, with the aid of Qarinah's shrinking LSD, he realised that Mephistopheles was responsible for the Prince of Sloth's perpetual sleep. Mephistopheles, exploiting the Belph's inactive nature, sought to throw Hell into chaos for unknown reasons...
Ford helped the Belph to overcome his lack of confidence and face his anxieties head-on- which took place on a bowling alley controlled by a Mephistopheles of gigantic proportions. While Ford was busy grappling with another of Mephistopheles' psychic powerful appartions (his own alter-ego, Easy Man) the Belph faced down Mephistopheles on the bowling lane. The Belph caught the boulder-sized bowling ball and returned it to his attacker with force- felling Mephistopheles to the floor.
Once defeated the Belph was in control of himself. Waking he applied himself to the improvement of his realm; New Angelinos. Ford took responsibility for Mephistopheles- intending to termporarily putting him in Pandora's Box before a more suitable solution could be found.
Season 4
Confined to Pandora's box since November 1987, he was next encountered almost a year later in October 1988. Time operating differently in Pandora's Box then it does on the earth realm this meant he had been confined for the equivalent of ten years. Bitter at his failed coup attempt he stewed in his resentment for Ford.
Several years into his imprisonment he happened to chance upon the deepest point in the whole of Pandora- The Abyss. He divined that this was place wherein any who enters it brings their own psychological battles with them- and it turns one's own Aspect against oneself.
When Huitzilopochtli, now crippled from the events of his climatic beat-down with Ford, was confined to the box Mephistopheles saw an opportunity to slither his way back into a position of power in Pandora's Box. As insignificant and relative as that power may be. He used his knowledge of The Abyss as a bargaining tool for his power- presenting it to H as a tool of punishment that he could wield over the other inmates of Pandora's Box. He was now Huitzilopochtli's second in command.
When Ford entered Pandora's Box to retrieve a locket of Hope's hair that had been taken by Huitzilopochtli, as well as taking the criminal Nani Nox down, he was confronted by his entire, budding Rogue's gallery. Ford didn't shy from Mephistopheles' plan to throw him into the Abyss- in fact he volunteerd to enter himself. Ford challenged Huitzilopochtli to do the same, which the proud Aztec God accepted.
Ford emerged victorious from the Abyss. Huitzilopochtli did not. Nervous that his power was threatened he called on the other inmates to rush and kill Ford. Ford, placid and diplomatic, swayed the audience of antagonists to stand down and face themselves.
Mephistopheles was unbowed and pettily called out 'No, no, no, no, no, no, no! Don't listen to him! Rush him!'. Miclantecuhtli, the Aztec God of the dead, was the only one to step forward... and lifted Mephistopheles above his skeletally thin shoulders to throw him over the edge into the Abyss.
Mephistopheles fate remains unknown.
Mephistopheles emerged from The Abyss as Doubt, rescued by his son, Payne. By remaining hopeful and refusing to be affected by his powers, Ford Corvin negated Doubt and caused him to cease existing.