The traditional Mephistopheles is a demon or a devil who is willing to purchase human souls in exchange for the desires of the heart. He is the devil who will meet at the crossroads to give musicians inspiration; he is an exacting cosmic lawyer who will exploit any loophole he can find in order to entrap your soul.
In traditional D&D lore, Mephistopheles is the ruler of the eighth level of Hell; Cania, and he is Asmodeus’ greatest rival for control of the nine hells. No one is entirely sure WHY Asmodeus allows Mephistopheles to openly scheme for control of Baator. He is calculating, patient and brazen in his ambition for Asmodeus’ throne, but he is also prone to fits of unimaginable fury.
I offer here, my interpretation of Mephistopheles.
My Mephistopheles materialized out of a need to have a devil in charge of making unholy contracts, and diverting otherwise heroic heroes’ attention in ways that benefit the ambitions of the nine hells. He has the power to make things happen. Almost anything a mortal could desire, Mephistopheles can make arrangements to obtain. He is not unlike a mob boss; he can get you what you want… At a very steep cost.
Obviously, he is a common patron for Fiend warlocks.
So, if we’re going to have this entity who grant mortals whatever they wish, we need to consider a few things.
What is the source of his power?
Why does he make deals with mortals in the first place?
Why is it that he isn’t afraid of reprisal from other deities?
What sort of things does he want in return?
Why does anybody trust him?
In my cosmology, there are Titans > Gods > gods > lesser deities > most mortals
Titans are indisputable forces of nature. Order, Life, Time, Change, Death, Fire, Io, and hundreds of others. They are the progenitors of the gods, who emerged from the ancient chaos and established the firmament of the worlds. Most of the Titans are long-dead, but a few of them remain. Although not very many, even among the Gods, are aware of it, Mephistopheles is the incarnate remains of the Titan of Order.
His will once brought the entirety of the cosmos out of chaos, and even in his fallen state, reality is somewhat mutable for him. Mephistopheles has had a long career of wheeling and dealing in the cosmos. He has a long list of mortals, and deities, who owe him something. Failing that, he can always exert some of his old power, and will something into existence… An ability that many of the upper deities lack.
When the Titan of Order awakened, it was absolutely disgusted with the chaos that surrounded everything. Over millennia, it slowly freed other beings from this chaos, and wrote the immutable rules of the universe. Order ruled over the other Titans with an iron fist, and held the other titans to the rigid and perfect reality that it had originally envisioned.
Of course, the other Titans eventually rebelled against Order’s rule. Order could not be slain, it could be contained. The other Titans stripped away much of Order’s power, and incarnated it in the current form. Additionally, they placed a powerful, eternal curse upon him.
Mephistopheles is very angry about his loss of power, and he seeks to restore himself in some way. Mephistopheles firmly believes that the entirety of existence is in a fallen state, without him as the supreme ruler. Mephistopheles works towards a future where he can challenge not only the gods, but the remaining Titans (Queen Tatiana, Death, Time and Change) as well.
Mephistopheles’ other great motivation in life is to fight against the “true chaos”, the beings that live beyond the bounds of reality and hunger after his glorious creation. Mephistopheles is often willing to make deals that do not favor him at all, if it means screwing over the Great Old Ones in some way.
See above. Mephistopheles existed before every member of the current pantheon, and he will exist long after them. He is not afraid of any one deity, or even an alliance of multiple deities. However, he IS aware that there are limits to his power; that was the whole point of imprisoning him in the first place. He is afraid of an alliance between pantheons, however. He will not suffer an alliance between Baator and Celestia, for example. (Neither would he allow an alliance between the dragon Gods, and the giant Gods.) Mephistopheles pulls the strings so that, should his chance of revival come, he will be unrivaled in the cosmos.
Now, Mephistopheles is generally allied with Asmodeus, which is why he has decided to dwell in one of the nine hells. Asmodeus hates most other deities, and their mutual interests (the killing of deities) often align. However, they are not tried-and-true allies.
Mephistopheles is an exceedingly genre-savvy Devil. He has seen across the dimensions, where mortals have spilled the blood of gods. Should the need arise, Mephistopheles wants allies that he can count on to bring down a threat. Or, to spark off an inter-pantheon war, if it suits his interests.
He wants heroes in his pocket.
Hearkening back to his origin as the Titan of Order, Mephistopheles cannot abide the “existence” of the Great Old Ones.
(It can be argued that the beings beyond the bounds of reality don’t actually exist, because at no point were they willed into existence by the Titan of Order. However, the academic argument over the existence/non-existence of the Great Old Ones is a moot point when they actually show up to devour whole sections of reality.)
Mephistopheles will go to great lengths to frustrate the efforts of the Great Old Ones; ANY of them really. He visits terrible punishments upon those he suspects of dealing with them, and reserved special places in Cania for the punishment of Chaos Priests.
To put it simply… Most people don’t. However, most people don’t realize that Mephistopheles is possibly the most lawful being in existence. Mephistopheles hates those who would lie, and for him to commit a lie would violate a deep aspect of his own nature. If Mephistopheles commits to something, it can be counted on to be done.
The premise of Mephistopheles is that he is a Devil who does deals. He can get anything done, if there is something he wants, he can acquire it… Or just will it into existence. However, there is a drawback to this. The Titans who survived the war against Order placed a powerful curse upon his current form, which they force him to disclose before beginning any contract negotiations.
Now, it should be mentioned here that there is also a more 'informal' curse against Mephistopheles. Most deities either hate Mephistopheles, or they owe him something. Deities who hate Mephistopheles are generally hostile to anyone who has ever made a deal with him. Do what you will with that.
As one might expect from an individual as slavishly lawful as Mephistopheles, he is regarded in my setting as the God of Lawyers and Contracts. Although an actual priest of Mephistopheles is hard to come by, and few Warlocks would admit that he is their patron, Mephistopheles is often invoked at the end of mundane contracts.
“May the Lord of Lawyers visit his curse upon me, should I renege my word.”
Your mileage may vary on how often the Lord of Lawyers pursues those who renege on contracts, but it does add a nice, spicy flavor for you to use, when your players make deals with NPCs.
If your players, or your public at large in your setting, are unaware that Mephistopheles = The Lord of Lawyers, you can totally have public shrines to the Lord of LAwyers where people go to get their contracts notarized. (It made for an awesome revelation in my games!)
Now, if your players are anything like mine, they are constantly getting themselves muddied up in the business of the cosmos. They may or may not run afoul of a deity or two. It can be fun to have your high-level players put on trial by a wronged deity, and have Mephistopheles appear as a lawyer for the defense, or prosecution. (Personally, I am in favor of The Devil as a Lawful Neutral divine prosecutor, so I tend to have Mephistopheles appear as the prosecutor when this happens.)
The primordial origin of vampires is something I am currently working out in my setting. I haven’t got the details in perfect order (yet), but Mephistopheles had something to do with it.
To me, it makes perfect sense (Also, there’s a joke in here somewhere about lawyers and vampires).
In the OG vampire novel, Dracula had sold his soul to the devil at some point, in exchange for a terrible kind of immortality that comes at the expense of the living. Vampires follow a rigid set of rules (cannot enter houses, cannot cross moving water, must count small things, etcetera); it seems perfectly fitting to me that vampires are the servants of Mephistopheles.
Now, Vampirism is still possible to spread via bite. Here, we follow WoD rules; each generation removed from an OG vampire loses some amount of power. Vampires who made original pacts with Mephistopheles are near-god like in terms of power; they are fearsome beings, enslaved directly by Mephistopheles for his dark bidding.
Mephistopheles does not entertain requests for vampirism often. For a mortal to even come to his attention as a candidate for vampirism, they must be quite powerful, unfettered to any other deity, and an exceptionally cruel person. (It takes an especially selfish and violent soul to entertain the idea of blood sacrifice to sustain themselves).
An original vampire is largely free to their own will, but must obey Mephistopheles, if he calls them to work. Mephistopheles does not allow his vampires any loopholes on killing. The “hunger” a vampire feels is less about a drive to find sustenance, and more about a compulsion to make sacrifices to their Dark Lord.