Mephistopheles

Sometimes shortened to Mephisto and once under the name of Molikroth, was the lord of Cania and most powerful archdevil next to Asmodeus himself. Hell's greatest wizard was a walking contradiction, on the surface the cool and calculating Cold Lord and beneath that the grandiose and hot-headed Lord of Hellfire. A retired Arch Devil who now goes by Mr. Strickland and spends his time on Bral.
Mephistopheles was a being of razor-sharp instinct, careful suspicion and prodigious brilliance, a cunning genius with an unparalleled understanding of Hell's political dangers and a great capacity for patient deception. Foremost wizard of Baator, his ordinary speech was like a whispering wind and his cool, pleasant demeanor gave him the outward appearance of a princely gentleman. He came off as sophisticated and charming when he spoke, an intellectual force of understated wit, reason and self-restraint, and embodied the casually crafty aspect of Hell's evil. However, this was by no means his ordinary behavior, but a facade like Dispater's which disguised his true personality, a veneer of elegance as carefully crafted as his traditionally infernal appearance. Despite his courteous persona, Mephistopheles was an unstable individual on the inside, the contrast between his cold surface and fiery core a perfect example of his existence as a walking contradiction.
Mephistopheles was a vicious being with an outrageous temper, who when alone in his palace frequently flew into violent rages, his quick wit burning away when met with his underlying hate and frustration. In his shrieking fits of terrible wrath he would start tearing at his own skin and destroying his surroundings in explosive outbursts of fiery, magical destruction, his unpredictable eruptions of rage having been his undoing multiple times in the past. Although his conniving intelligence was certainly real, Mephistopheles was an emotional entity that was ultimately driven by his passions.
Mephistopheles suffered no distractions from his focus, his studious pursuits being of utmost importance to him. Though he would entertain visitors purely for his own amusement, a rarity among the archdevils, he hated any unwanted distractions and rarely gave time to anything not worth his personal attention. He was known for disintegrating underlings for the slightest annoyance, only allowing a few devils to speak without being spoken to, and sometimes executed his servitors based on the suspicion that they would bother him. Further cementing him as a contradictory entity was the strong but flickering nature of his focus.
Mephistopheles's great intelligence often ended up mixing with his obsessiveness, as in his pursuit of knowledge he became fascinated with the most minor details. Though this allowed him to delve deeper into topics than typical wizards, his unrelenting focus had to be tempered by his responsibilities, and was ultimately undermined by his mercurial behavior. When forced by some political circumstance to stop what he was doing, there was a chance upon returning that some new project would catch his eye, at which point that research would become his new top priority. Because of this cycle of undivided attention followed by casual neglect, Mephistopheles had many useful discoveries ready to be accessed that he simply didn't know about.
Mephistopheles was a being impervious to the cold, not just due to having ruthlessly exposed himself to Cania's coldest temperatures, but because of his unrivaled mastery of hellfire. A corrupt and extremely potent energy with the properties of flame, hellfire was unimaginably hot and created by tapping into and mastering the profane essence of Hell and channeling into a usable form of power. Unless he chose to repress it, his body would emanate dark flames, causing anyone who touched him, or anyone near by if he evoked into a burst around him, to be scorched by the unholy energy.
To further his mastery of fire, Mephistopheles took up the study of wizardry, specializing in evocation magic modified to taint his foes with foulest evil, with a noticeable disinterest in enchantments and illusions. Given the nature of baatezu politics, Mephistopheles rarely traveled alone, often bringing two bodyguards with him anywhere he went and able to summon a few gelugons or pit fiends, often choosing the latter, while his accompanying servitors kept the enemy busy. Given his sense of self-importance, he believed anyone who dared attack him deserved no less than utter obliteration, and so let loose a barrage of offensive magical destruction from the rear of the fight, teleporting away and leaving his allies to their fate if met with a real threat.
Though lacking the most powerful spells as a wizard, Mephistopheles' innate spell-like abilities more than made up for it. He could cast all sorts of ice and fire related spells, showcasing his mastery of both elements, such as cone of cold, fireball, and wall of ice or fire, meteor swarm being his most powerful and the one he could use only once per day. He was also capable of inducing fear, either through an aura or via his gaze.
Mephistopheles' favored weapon was a three-tined military fork or ranseur. He was known to have different types, such as one that could switch between inflicting fire, cold, and electricity, each three times per day. Another switched between burning eternally and being covered in frost, and allowed the wielder to focus hellfire spells to be more devastating. Aside from that and other magical items, the laboratories in his home citadel were filled with spellbooks containing nearly every known arcane spell, allowing him to prepare almost any he pleased.
Mephistopehles's realm was the gloomy, frigid wasteland of Cania a realm of cold indescribable with words so bitter that it was practically alive. Cania outmatched the arctic sea of Stygia, which at least offered some relative form of comfort via the River Styx, in sheer harshness, the cold-hearted frost more like that of the Plane of Ice with the temperature in most areas being below −60 ℉ (−51 ℃). Without magical protection, the merciless chill would quickly kill most life in hours, if not minutes, if not seconds, depending on how prepared they were. Any warm-blooded creature could only survive for a few hours by wearing cold-weather clothes, and going to sleep (or otherwise being unable to move) was a death sentence in most cases.
The icy hellscape suffered from violent snowstorms seemingly brought on by Mephistopheles himself, the blinding, howling wind spraying ice and dust that stung at best and tore flesh from bone at worst. Filling the wild, frozen expanse were jagged, cyclopean mountains and colossal glaciers that emanated a dim blue-white light, the only natural source of illumination in the entire layer. The glaciers endlessly grinded against and crashed into the mountains with the speed of a running man, causing avalanches consisting of several thousand tons of snow and icy rock to regularly collapse and overwhelm those below. Death in Cania was swiftly followed by freezing, which encased the corpses in clear coffins of ice, preserving the expressions of anguish even thousands of years after death presuming they weren't destroyed.
Despite these conditions, some small amount of life was able to carve out a hungry existence in Cania, the icy caves, hidden mountain valleys and deep crevasses serving as decent hiding places. Fiendish dire polar bears and wolves were said to prowl the land, having evolved effective immunity to the bitter cold, and supposedly remorhaz and glacier worms of great rarity were also present. That withstanding, Cania was a layer so cold that even many devils found it inhospitable, the typically lower-layer dwelling pit fiends largely avoiding it. Only the gelugons, the primary residents and second in authority only to the pit fiends, although they were mainly guards, servants, and messengers, could comfortably exist in Cania. Even after their self-exile to Cania's relatively warmer fringes, they were still the most common devils in the plane. The few kocrachons that inhabited the layer were only mildly comfortable and left discipline mainly to the gelugons, although white abishai and hellcats were also found in some places.
Cania was, in effect, a giant laboratory/testing ground for the experiments of Mephistopheles and his scientists, where immense quantities of arcane energy could be released into the wastes without consequence. The testing of new spells, magic items and other supernatural techniques regularly caused local devastation, and the libraries and data storage areas of the plane were spread out enough so that one unexpected cataclysm didn't accidentally destroy other research. Insights could be made regarding the nature of the research by simply observing from a distance, and renowned archmages such as Mordenkainen were known to visit the horrible tundra looking for lost lore or information to help them in their own endeavors. As a result of Mephistopheles' wavering attention, supervising sages and spellcasters with incredible research could be found in long forgotten-citadels, as buried in ice and snow as they were in bureaucracy.
Even uninhabited cities in Cania housed many secrets now buried under ice and only visible as distorted shapes, and when unearthed appeared prosaic and alien in architecture. Before Asmodeus even descended into Hell, Cania was a realm of grand cities, the remnants of that ancient power now preserved in ice in the form of strange spined creatures battling devas and archons, as well as their works, the icy tombs, lost libraries and palaces now haunted by ghosts and terrible undead. What kind of creatures dwelt inside these buildings was unknown and most devils would rather just leave the ruins alone, although the ice-embedded buildings were able to provide some shelter against Cania's cold. Perhaps it was this legacy of ancient power that compelled Mephistopheles to make his home in Cania, as it was said that it was in these tombs that Mephistopheles learnt of hellfire and obtained weapons powerful enough to give even Asmodeus some pause.
The most famous example of these lost cities was Kintyre, encased between two icy mountains thousands of feet under the several ton glacier T'chemox. It was once inhabited by a duke who rebelled against Mephistopheles who, in response, entombed the city in ice, and many were loathe to try and undo his handiwork for fear of provoking his ire. Once it was only being explored by curious adventurers, but after recovering ancient texts, Mephistopheles learnt that his unfaithful duke's tomb may have been hiding several ancient relics invaluable to hellfire research, the Duke of Brimstone's anger once again undermining him and forcing him to organize expeditions into the forgotten, warded keep.
Mephistopheles' primary base of operations in Cania, and perhaps the only notable area on the entire plane, was the citadel of iron and ice, Mephistar. Mephistar was carved from the sparkling ice of the glacier it overlooked, the tremendous mountain of ice Nargus which, while temporarily settled between surrounding glaciers, could be controlled by Mephistopheles to steam over any lesser glacier. The city was like a gleaming, translucent, blue-white jewel of ice perched at the glacier's edge. Though several misinformed poets quipped about how Cania was as cold as Mephistopheles' heart, they weren't completely wrong about his home mirroring him; just as Mephisto's cold exterior masked fiery passion, so to did Cania's cold mask the oddly warm and inviting nature of Mephistar. Even before his hellfire experiments, Mephistar had lavish, heated baths and scented fires, and when the huge doors of the walled citadel were opened, a rare occasion since most devils could teleport, massive steam clouds poured out, though they rolled over the side of the walls anyway.
It was from within this fortress city that Mephistopheles held court over ice devil legions as well as spinagon and cornugon staff all ceaselessly following strict, scheduled activities. The citadel's levels seemed endless, but the three topmost terraces housed thousands of safe and cozy living quarters vaulted impossibly upwards, the bottommost levels being cramped and warren-like and the topmost residences being grand suites. Befitting the strange kindness of Mephistar, its populace was reassigned quarters based on promotion and demotion for the mutual benefits of both sides, superiors and inferiors kept separate to avoid the distress of the former or terror of the latter. It was within the higher regions of Mephistar that Mephisto's true palatial manor was placed, a castle where all furnishings and contents, even his throne, were constructed of subtly and intricately detailed ice.
Recently however, Mephistopheles's experiments in hellfire had been proving detrimental for the overall stability of his domain. The foggy cloud around the city had grown more established, and the details of his estate had become more muted as they thawed and puddles formed. Already the gelugons, once perfectly fine in the somewhat warm citadel, had begun leaving for the outer reaches of the plane, replaced by increasing numbers of pit fiends, cornugons and barbazus. The Garden of Frost, a perfect facsimile of an organic garden in Mephistar and one of the few beautiful, if saddening, places in Hell, had to be repeatedly blasted with cones of cold to keep it together. From the 99-story School of Hellfire elsewhere in Mephistar came toxic clouds of effluvia that left a fair fraction of the citadel uninhabitable for non-devil inhabitants. Eerie bursts of hellfire, were becoming signature characteristics of Cania, and the inherent risk of Mephisto's hellfire strategy had to be growing more and more obvious, even atop the Cold Lord's slowly melting throne.
From the wizard's tower that was Mephistar, Mephistopheles performed many tests, to discover more about arcane magic and the nature of the planes, his most recent pet project being his hellfire obsession. He had spent a great amount of time mastering and experimenting with the new, magical fire, distracted him from the needs of his formerly favored minions, the gelugons, his realm's stability and his soul-harvesting efforts.
With Cania's old power structure virtually upended, the ice devils fled to the mountain Gelineth and formed a retreat known as Nebulat, which stuck out of the mountain's side like a crystal fungus. Though none would directly condemn him, the discontent devils made many plans to resolve their situation, some scheming to undermine his lead researchers by finding or planting evidence of treachery, creating a new type of ice magic to win back his interest, trying to correct his behavior and others just plotting to replace him.
Meanwhile Mephistopheles's attempt to grow his cult using hellfire had put him in large amounts of divine energy debt to some of the other archdevils, particularly Dispater and Levistus. He was taking a serious gamble, for though his success could ideally grant him the largest and most popular cult, failure would leave him devastated, and his investors would likely sabotage him if his risks seemed likely to pay off.
One might wonder, given the untrustworthiness of his pit fiends, how Mephistopheles was able to retain control over his domain, much less devote almost all his time research. This was thanks to his chief servant, the extremely powerful pit fiend Hutijin said to be one of Hell's greatest dukes and perhaps the quintessential duke. He was responsible for guiding Cania's pit fiend nobles, protecting it from all but the most concerted attacks. Without him, Mephistopheles's domain would soon break out into open civil war, which if combined with outside interference against the weakened Cold Lord would certainly spell Mephisto's end. Yet despite having the power to challenge his master, Hutijin was famously unwavering in his loyalty, treating Mephistopheles as a near-god. Some theorized the Cold Lord had something over Hutijin, yet he never abused the pit fiend's trust, the stability of his domain without him likely playing a big part in that decision.
Mephistopheles was the sire of Raphael, a powerful and manipulative cambion who sought supremacy within the Hells by dominating the Absolute. Perhaps in an attempt to frustrate these plans, Mephistopheles employed the incubus Haarlep as a distraction to his wayward son. His son's obsession with the crown of Karsus was what drove him to the mortal plane.
Mephistopheles's recent insights into hellfire gave him a new way to appeal to mortals, even despite the fact that it's diabolical nature typically required a sacrifice of the user's own vitality to be called upon. The beauty of offering hellfire laid in its accessibility; most types of magic required the user to slowly refine their skills and/or progress along a path of understanding on how to use it, a dangerous road of adventure being a frequently used method. Mephistopheles's cultists could offer the dark energy to even the most inept persons of influence, granting them an easy, painless, path to power, prestige, and dominion. Because this plan was as much a method of gaining souls as it was of increasing Mephistopheles's influence on the Material Plane, being lawful evil wasn't a barrier of entry to join the cult.
Mephistopheles's plans to become a god finally came to some form of fruition during the Spellplague. Mephistopheles had persuaded his half-breed son, Magadon, to release the devil inside of him and therefore bring himself and his fellow companions Erevis Cale and Drasek Riven to Cania through some manipulation of Cale's ability to travel through shadows. Mephistopheles then proceeded to kill his half-breed son after Erevis promised Mephistopheles a portion of the god Mask's divinity. He did this as part of the agreement, not that he discussed it with Cale, saying that he would kept half of Magadon's soul with him as collateral until the delivery. Erevis later returned to Cania and sacrificed his life for the return of Magadon's soul, giving Mephistopheles the divinity he so desired, although with an unexpected cost.
It was at this time that Riven, who used his new demigod powers obtained from absorbing some of Masks's divinity to travel to Cania, paid Mephistopheles a visit. Riven attacked and nearly decapitated the archdevil, and told him that if he ever stepped out of his domain that Riven would utterly destroy him. Mephistopheles replied by telling Riven that he would come back and would be waiting for him though he himself seemed to think that Riven would come back under the impression he would return for Cale at some later date. Even in the obtainment of divine power, his defeat withstanding, Mephistopheles was still undermined. Once Mephistopheles had fully recovered from Drasek's ambush attack, the insult to hours of injury revealed itself in the form of an icy cairn at the bottom of his domain, at the bottom of which laid Erevis. The rest of the divinity cheated from him was still down there, but no matter what he used, whether it was the power of hellfire, legions of furious devils, or teleportation, he couldn't enter or even scry what lurked beneath the shadow-leaking ice.
Making this worse was that during the Spellplague, Asmodeus had managed to absorb the half-murdered Azuth, who had simply fallen through the Astral Sea into Hell. Mephistopheles's divinity was only a fraction of Mask's power, which itself was only a fraction of the power taken from Kesson Rel, and while he was trying to finish obtaining the last of it, Asmodeus left him second-rate through sheer luck. Though he realized that the unbreakable ice was likely some ploy of the Lord of Thieves, Asmodeus's calls to his domain were filling him with dread and pushing him to act. He feared Asmodeus was prepared to punish him for trying to dethrone him and, befitting his ego, would rather try to obtain godly power and orchestrate a coup in his limited time than beg for mercy while hoping to evade his wrath. As Mephistopheles suspected, Mask was trying to manipulate him, although not exactly in the way he thought.
In 1484 DR, after a century of trying to break the ice, Mephistopheles chased the one clue he had, the existence of Erevis's son, Vasen Cale, believing he held the secret to getting to the bottom of the cairn. This was in fact, all part of Mask's plan; Vasen was a powerful and dedicated servant of Amaunator and the reunited father and son duo managed to strip the fragmented remains of Mask's divinity from all holders. Though Vasen intended to have his father receive the power, Riven decided to take on the divinity, effectively becoming the reincarnated Mask. Mephistopheles meanwhile found his plans thwarted, forced to flee the scene through teleportation without any divine spark while choking on his own blood and guts. Claiming to be retired from his responsibilities in hell. 
"I knew I smelled the tang of a goddess. This, too, I claim as mine." - Mephisto
"There are few problems that cannot be solved through the application of overwhelming arcane firepower." - Mephisto