Not a lot is known publicly about this figure, but in the underworld is known to be the guy you go to if you want to gain some power temporarily.
Demonic-looking, horned with dark blue skin, and a thin tail with a small spiked end. Generally looks very handsome however. Think D&D Tiefling. Has a coven rune on the back of his right hand. Generally stylishly dressed. Has forked tongue that appears to be silver in color.
Has a sense of honor about him, and won't screw over someone he works with. Will always strive his best to accomplish a promise he sets. Generally wants people in good standing or with honor he works with to succeed. Works with criminals and heroes equally.
A case-53 , mutated biology makes him appear to be like a demonic figure of some sort, though his words are honeyed, and are generally more likely to be accepted. He also is generally likable, and easy to get along with.
His actual power is a fairly powerful trump ability. He can grant a variety of powers, though they often fall into the master, brute, striker, blaster, or changer categories. Abilities often have a demonic or biblical theme. Cannot grant a precise ability, but can generally decide the broad category an ability will fall into (I.E. deciding it will be a brute ability, but not precisely which one). Over the course of a week, the person with granted powers will begin behaving more erratically and aggressively, at cap acting in sadistic ways, actively seeking out fights. As they become more erratic Mephistopheles gains a portion of the ability they got, until he gains a full-powered version after a week. Mephistopheles can cut off the power given at any time, and people will lose their aggressiveness/irrationality at the same rate that they gained it until it is gone. Mephistopheles can grant 5 powers this way at a time. Parahumans can be enhanced with this, though they only gain roughly half of what an unpowered human would gain, and the resulting ability typically complements or enhances their already existing ability.
Trigger Type: Case-53 (Trump/Master)
Open to working with heroes and villains, though more often finds villains coming to him for services. Charges selectively based on how he feels about the person. Is fully willing to cut someone off if they are getting too erratic from use of his power, and if people keep coming back too quickly will begin to attempt to drive them off, usually by demanding exorbitant costs, mostly for the protection of the sanity of the client. Runs his own small organization with well-trained people who rotate in and out of using his ability to minimize the mental influence of his ability.