Complete Monster/The Elder Scrolls

The vast world of The Elder Scrolls has many characters, and the villains come in many different varieties, and these are the absolute worst that this series has to offer.

Arena

 * Jagar Tharn, Battlemage to Emperor Uriel Septim VII and the first Big Bad of the series is more of a stereotypical classical villain, but he still fits the bill. While appearing as a loyal servant to Emperor Uriel, he secretly covets power over the empire of Tamriel for himself. And to that end, he seals the emperor and a trusted general of his away in a hellish plane of Oblivion where they're tortured with horrific nightmares, and would have been subject to this horrifying fate for centuries before finally dying thanks to time passing by slower in this realm. After disguising himself as Emperor Uriel, Tharn sought to run the Empire into the ground by getting the countries that were a part of it to tear each other apart in brutal wars, some of which he personally financed himself. The scumbag even sold out the Empire to the Daedra by making a pact with the Daedric Prince of destruction Mehrunes Dagon, and allowed him to invade and destroy the Battlespire, a training ground for future battlemages which resulted in almost all of the apprentices and teachers dying at the hands of the Daedra. All in all, Tharn was an incredibly selfish, slimy, power hungry bastard who decided that every bit of power and influence he obtained through betraying countless people was well worth the cost.

Daggerfall

 * Daggerfall has two rather nasty contenders, and they are the former (deceased) king and the then-current queen . Long story short, their designated-heir son was chronically ill and fairly uninterested in invading neighboring countries for their land, the latter of which was the kind of thing his parents liked doing when they could get away with it. Not only did they produce some more children and partially disinherited him, his interest in scholarly pursuits.

Morrowind

 * How Dagoth U'r of Morrowind became what he is, is questionable, but the moral nature of what he does is undebatable. He betrayed the wishes of his best friend and tapped the powers of the Heart of Lorkhan for godhood -- he invented the Corprus disease, which warps the bodies of its victims and shatters their psyche, to produce his soldiers -- he blighted the land of his own people with endless storms of volcanic ash and foul sickness -- he is in the process of recreating Numidium, an originally Dwemer-created machine that is responsible for destroying an entire race of people -- and he plans to spread the Corprus plague across the entire continent of Tamriel and invade all of its nations, so that he can commit complete genocide against all non-Dunmer races. In a world of Black and Grey Morality, Dagoth Ur is the pitch void.

Oblivion

 * Then there's Umaril the Unfeathered, the immortal half-Ayleid demigod sorcerer-king, who made a deal with one of the Daedra (admittedly one of the Chaotic Good/Neutral ones), then, after being temporarily killed, returned to destroy the gods who had empowered his killer. He brutally murdered at least a dozen members of the clergy and then wrote messages on the floor with their blood. As a taunt.
 * Kurdan gro-Dragol starts off as a particularly brutal loan shark, until you discover that . And then, as if to rub salt in the wound, . Needless to say, taking this bastard down is very satisfying. Delivering the news to the recent widow, less so. At least Kurdan will no longer hurt anyone.
 * Big Bad Mankar Camoran of Oblivion is a Magnificent Bastard who gives epically impressive speeches that you have to admire, but he still created a pocket dimension in which he locks people in gibbets and sinks them into lava, but not before making them immortal. And the kicker? These were his followers. During Oblivion, Mankar’s goal is to summon his master into Tamriel so Dagon may destroy the world and create a new one in its place, one that coheres with Camoran’s Social Darwinist beliefs. Not only does Mankar aide Dagon’s Daedra in attacking the mortal world, he also orchestrates the assassination of Emperor Uriel Septim, as well as his children. He even had the city of Kvatch completely destroyed in a failed attempt to kill Uriel’s bastard son, Martin. While Mankor lures in his followers with promises of a paradise for their faithful service, this turns out to be a lie. Seemingly idyllic on the surface, Dawn’s Beauty, Mankar’s “paradise,” is really a hell where his followers are constantly killed by monsters, only to be resurrected and killed over and over again. His promise to allow any follower who loses faith to leave his paradise also proves false, as the grotto, which is said to be an exit from the afterlife, really leads to a torture chamber where the unfaithful are made immortal, locked into gibbets, and then dumped into lava. One follower who lost faith was forced by Camoran into inflicting this punishment on his friends over and over again. Dawn’s Beauty is said to be Mankar’s vision of how he believes the world will be once Dagon takes over.
 * An example who spans over several games, the dreaded necromancer Mannimarco is one of the series' most stand-out examples of pure unadulterated evil. A power-hungry Altmer mage who wasn't content with simply amassing a huge wealth of magical knowledge, Mannimarco grew to despise all life and turned to the dark arts of Necromancy after becoming obsessed with enslaving people's souls, soon starting up a coven of necromancers that became infamous for their cruelty and brutality. During the time of The Elder Scrolls Online, Mannimarco tricked a group of mages into weakening the boundaries between Nirn and Oblivion, allowing the absolutely savage and brutal Daedric Prince Molag Bal to spread his influence to Nirn, and gleefully assisted him in laying waste to the world as his Dragon. However, After this, a millennia passed as he accumulated enough power to ascend to godhood and left a mortal incarnation of himself behind that became hell-bent on destroying the powerful Mage's Guild. To this end, Mannimarco began to conduct research on Black Soul gems, horrible items that can be used to trap the souls of sentient beings for use in his necromancy. Horrifyingly enough, a person whose soul is trapped in a gem doesn't truly die and is completely aware of where they are. When a gem has been used, the soul is transported to a hellish dimension called the Soul Cairn, where they are kept in brutal, agonizing pain for all eternity, a horrifying fate he had in store for Guildmaster Hannibal Traven.  His reason for his needlessly ruthless vendetta against the guild is incredibly infuriating: he wants to destroy it as a way to spite an old enemy of his despite the fact that said enemy is long dead, which means that he has no real reason to be doing this. Thankfully, he can meet a karmic death of hilarious proportions should the player trap him in one of the Black Soul Gems he loves oh so much, an appropriate fate for this monster of an Altmer.

Skyrim

 * Skyrim has a lot of completely, utterly revolting people lurking about in the frostbitten country, though its biggest example is the literal monster Alduin: a cruel and arrogant black dragon and the firstborn of the Aedra Akatosh. By design Alduin is a World Eater whose main purpose in life is to devour all of the plane of Mundus in order to ease along the cycle of creation and destruction, but fueled by cruelty and power lust, Alduin goes far beyond his intended purpose and delights in needless destruction. He has had a track record of trying to devour reality far earlier than intended, and in one instance caused the corruption of the figure who would become the Daedric Prince Mehrunes Dagon, which makes him indirectly responsible for incidents such as the destruction of the Battlespire and the Oblivion Crisis. During another attempt at devouring reality, Alduin decided to completely shirk his duty and settled for conquering Nirn by leading armies of dragons to brutally enslave and reign over all mortal life while forming vile Dragon Cults in order to establish himself as a god. When he was defeated in the Dragon War and banished to present-day Skyrim, a furious Alduin decides to simply destroy the world far earlier than intended, and begins his newest reign of terror by burning the village of Helgen to the ground and slaughtering countless innocents. He flies around the country and continues to raise other dragons from the dead in order to have them raze Skyrim to the ground, but after a battle with the Dragonborn, Alduin flees to the Nordic afterlife of Sovngarde in an act of cowardice that's unbecoming of a dragon. When the Dragonborn chases him down, they see that he's hard at work devouring the souls of the honored dead and denying them a well-earned and glorious afterlife in order to boost his strength before his final battle with the Dragonborn and the heroes responsible for winning the Dragon War. While dragons are violent by design, the presence of multiple friendly dragons such as Paarthurnax as well as Alduin's willingness to break from his appointed duty at his leisure paint him as a freely monstrous individual, and perhaps one of the worst to ever grace the world of Tamriel.
 * As a whole, the Thalmor come off as the only purely evil faction in the game. But even among their ranks, there are two especially vile individuals who stand out.
 * The most outstanding example of pure evil among the Thalmor would be Elenwen, the cold blooded, insufferably smug ambassador of the Thalmor in Skyrim. Under her orders Talos-worshipping Nords are dragged from their homes and brutally tortured to death for their faith. When victims of her witch hunts are bought to her embassy, she's more than happy to get in on the fun herself and is so good at the art of torture that she's hailed as a hero by a particularly nasty underling of hers. And in case if you thought that her employees are safe from her wrath, they sure as hell aren't: she allows a servant girl of hers to be sent to the embassy's torture chambers due to a partygoer falsely accusing her of making unwanted advancements on him while knowing full and well that she wasn't, and she's more than willing to hand control over cities that she has troops stationed in to the Stormcloaks while being fully aware that they'll die at the hands of the Thalmor-hating rebels. She's so revolting that even her own Imperial-aligned allies barely tolerate her, with the heads of the Imperial Army raising no objections should you kick her out of a peace conference.
 * The second revolting member of the Thalmor would be Ancano, the Big Bad of the College of Winterhold storyline. While he initially seems like a halfway-decent guy that wants to buddy up with Archmage Savos Aren, he secretly wishes to get his grubby little paws on the Eye of Magnus, a powerful magical object. When he activates the Eye, he attempts to unmake all of reality itself just to show that he can, and spreads the chaos to the nearby town of Winterhold where he allows dangerous magical anomalies to run wild on the townsfolk. He also successfully kills, and recklessly tosses his hopelessly outgunned and underpowered flunky Estormo at the Dragonborn as a way to stall for time. Even before he outs himself as a villain, everyone (including the two Altmer women on campus) views him as an untrustworthy, sleazy creep, and no one's sorry to see him go.
 * Skyrim is also home to more than a few particularly nasty mages, one example being Sild the Warlock. Making his home in an Ancient Nordic crypt, he lures in explorers with tales of treasure and the like, only to trap them in his lair so he can torture them to death. He also raises the spirits of his victims and forces them to patrol the crypt and fight off anyone who could put up a fight against him, with the ghosts being aware of their situation and desperately begging you to end their suffering while also apologizing for attacking you against their will. When the Dragonborn meets him, he gleefully taunts them about how slowly he'll kill them, takes his sweet time in finding the right tools for the job, then comes back to slowly burn you to death if you don't escape your cage in time, and also mentions off hand that he murdered his assistant just because he didn't need to put up with her anymore. And to make things worse, giving his journal a look reveals that he wishes to find slower, more painful ways to kill people simply because he finds the concept of taking an innocent person's life sweet.
 * Another rather nasty mage would be Arondil, an Altmer Necromancer who is defined by one thing: he loves the dead. As in he really, really loves the dead, to the point to where he is a necrophiliac rapist. After being run out of his home town of Dawnstar, Arondil hid away in an ancient Nord crypt known as Yngvild, and defiled the spirits of the honored dead by resurrecting the Draugr (mummified corpses basically) in order to serve as his bodyguards and entourage. But it wasn't until he killed a milkmaid who accused him of being a stalker that he really crossed the line: he reanimated her as a phantasm used her as a sex slave and a body guard against her will. Not satisfied with just her, he has his servants go out and kill more women who get lost around his home, adding more and more unwilling subjects to his growing harem of undead sex slaves... thankfully, if you take the soul gems that enthrall his slaves, they waste no time in butchering him when their free-will is restored.
 * Thonar Silver-Blood uses the prisoners gathered in Cidna Mine as free slave labor in order to run his silver empire, which already makes him a pretty amoral douche. But the full extent of his evil is revealed when you do some digging into why Forsworn attacks are happening in the streets of Markarth. While his Imperial-aligned counterpart Maven Black-Briar of Riften is certainly an awful person, Thonar makes her look like a saint in comparison due to how far his corruption runs!
 * The Dragon Priests are pretty evil beings but there are two even among their ranks who qualify for this trope. There's Rahgot, a Jim Jones-style cult leader who was a coward that forced his cult to commit mass-suicide, even the children in order to dissuade an approaching army from searching his lair by forcing all of them to ingest a highly lethal poison. When one of his followers questioned him about the morality behind this deed, he had her brutally murdered for daring to defy him. There's also Hevnoraak, who had such mastery over the power of his voice that he amassed a following of people who he could torture for hours on end, all while they were helpless to resist his voice.
 * The dreaded Wolf Queen Potema Septim is considered in-universe to be one of Tamriel's few completely evil historical figures, and for good reason. She was a ruthless tyrant who indulged in dark arts like necromancy and led a brutal campaign against the Empire of Tamriel by tearing its provinces apart in bloody battles. She was also incredibly petty as well: she turned her own nephew insane by giving him a cursed necklace as a way to hurt his father, and sent a servant to be tortured forever in the Soul Cairn for mocking a dress of hers. It's no surprise that after she's been resurrected by a cult of necromancers (And she's no less monstrous after raising from the dead after thousands of years, as she seeks to lay waste to Tamriel with an army of the undead), Solitude's steward Falk Fire-Beard is absolutely terrified of the prospect that due to her lineage, she could very well be the legitimate heir to the Empire. In fact, if you want a proper look at what kind of a person she was, she's quoted as saying that she'd happily sacrifice all of her subjects to the Daedra as long as she can obtain a bit of comfort for herself.