In the fantasy world of Gielinor, where an average quest sees the world threatened by Humanoid Abominations, Evil Sorcerers, and Artifacts of Doom, there are some villains so utterly vile that they strike fear and hatred into the hearts of even the most veteran adventurers.
- Sigmund is a genocidal xenophobe willing to go to any lengths to see the peaceful cave goblin race driven to extinction. He is a leader of H.A.M., or Humans Against Monsters, a human supremacist-cult that believes all races perceived as monsters must be exterminated. Even his comrades consider his methods too extreme, and Sigmund eventually defects when he believes the organization has gotten too soft. His first attempt to destroy the cave goblins is to spark a war between them and the human city of Lumbridge, uncaring about the human lives lost, causing his former friend Duke Horacio to turn against him. When that fails, he tries to flood the goblin capital, but fails when resurrected cave goblin Zanik reveals his plot despite him having previously tortured her to death. Unwilling to give up, he tries to have Zanik run over by a dwarven train to cause a devastating war that would annihilate both races. After failing numerous times, Sigmund's final plot is to poison the cave goblin youth and personally lead his gathered army to slaughter the goblins as they're weak and defenseless. A racist and relentless warmonger, Sigmund served as one of Runescape's earliest and most evil villains.
- King Lathas Ardignas and Warmaster Lord Iorwerth are two power-hungry tyrants and the main antagonists of the Elf/Plague quest series. Iorwerth began his bid for dominance of the Elven capital of Prifddinas when he allied with the Dark Lord, a death-obsessed part of Seren. He cut off the Elven clans from communicating with their goddess, purged thousands of Elves in the ensuing civil war, and spent hundred of years hunting down the remaining rebels. In the present day he allies with Lathas, the King of Kandarin, who seeks to claim the entirety of the kingdom from his brother Tyras and destroy Camelot. Their master plan involves fabricating a great plague and having Iorwerth's clansmen, disguised as the Mourners, kidnap citizens of Tyras's kingdom and force them to mine a path to the Dark Lord's prison. They accomplish this by poisoning the city's food supplies and enslaving the civilians that appear sick under the guise of quarantining them, Lathas eventually tricks the player into assassinating his brother, but the player retaliates by warding the Dark Lord's prison. Iorwerth's last ditch attempt involves sacrificing the people of West Ardougne in a great ritual and using their souls to empower the Dark Lord, or failing that, using his own men as they are defeated by Tyras's vengeful soldiers. Lathas callously plans to turn the depopulated ruins into his own personal garden. In a world cursed by scheming Mahjarrat, rampaging Dragonkin, and wrathful Gods, the mortals Lathas and Iorwerth truly stand out for their willingness to sacrifice their own people to fuel their megalomania.
- Nomad, the Scourge of Souls, is an extremely powerful warrior-mage whose grand machinations have led to the untold suffering of both the living and the dead. Nomad is first introduced as the creator and curator of the Soul Wars minigame. The quest "Nomad's Requiem" reveals the great game to be nothing more than a method for Nomad to siphon the souls of its dead players through the soul obelisk in order for him to greatly empower himself and overthrow his former master. Although believed dead, he is later revealed to be alive by devouring the souls he captured and tries to evade Death to prolong his life. Saved by the player to be used for the heist in "Dishonour among Thieves", Nomad again betrays his comrades and god, Zamorak, to further his own goals. His final appearance in "Nomad's Elegy" shows just how far Nomad has fallen into evil to achieve his goals. He captures the fortress of Icthlarin and sets up a giant soul obelisk to capture the souls of everyone who has died on Gielinor and twist their souls into a terrible new form. These souls, still in unending agony, are shaped into a new god that Nomad controls and intends to use to "save" Gielinor from the Gods, but his pettiness, constant mockery, and monstrous methods show how hollow his plans truly are. Consumed by his pride and lust for power, Nomad believes himself to be the savior of Gielinor and its people when he is nothing more than a delusional madman who sought to rule the world with his own twisted abomination serving as his figurehead.
- Lowerniel Vergidiyad Drakan is the Lord of Vampyrium and Morytania and the main antagonist of the Myreque quest series. Much of Drakan's early life was rife with betrayals in his attempts to gain power. He poisoned his predecessor Lord Malachi to assume control over the vampyre race, and he later sided with Zamorak against his then master Zaros on the conditions Drakan could gain his own kingdom. When the God Wars began, Drakan found his opportunity in the Icyene kingdom of Hallowvale. He forced Icyene Queen Efaritay to surrender by threatening to kill her husband King Ascertes, turned Ascertes into a vampyre anyways, and ordered the newly created Vanstrom Klause to spend millennia trying to hunt down and kill their son Safalaan. Establishing himself as the new dictator, he created magical storms to eternally blot out the sun and turned the once-lush Hallowvale into the haunted, fetid swampland of Morytania. The remaining Saradominist humans and Icyene were enslaved and transformed into the hybrid Vyrewatch to serve as Drakan's Secret Police. Drakan's greatest act of evil came when he created "bloodfarming" to feed his people: the remaining human populations were forced into ghettos and routinely drained of blood to the point of severe anemia. This ultimately leads to revolution by the human Myreque and disgusted vampyres led by Vanescula Drakan. In the end, when he is slain by the Player Character, Drakan states that he held no regrets in his life for all his atrocities. Personifying the very worst aspects of vampyre society, Drakan sought only to lead his people to an evermore violent and bloody future.
- Sliske, the serpent-tongued, is a Mahjarrat defined by entertaining himself by spreading chaos and misfortune as his sole motivation for existence. Born from the dreams of the stillborn Elder God Mah like his kindred, Sliske proved to be a master manipulator at a young age when he murdered the younger brother of his friend Azzanadra and blamed it on the Mahkorrat tribe, who were wiped out by the Mahjarrat in retaliation. Even after coming to Gielinor in the 2nd Age, Sliske entertained himself by turning his people from Icthlarin to Zaros and by creating theater shows performed by People Puppets while he served as the head of the Secret Police for the Zarosian Empire. He also loved playing the eponymous role in Deal with the Devil by twisting the wishes of people such as the Barrows Brothers, Gregorovic, and Linza by making them his undead slaves. His evil reached its peak in the 6th Age when he murdered Guthix and tried to incite new God Wars by using the Stone of Jas as a prize for the returning younger Gods. He also sought to make life a living hell for the Adventurer by constantly trying to turn them into a wight and torturing those they cared about when he failed. Ultimately, his master plan involved having the Gods escalate their conflict to throughout the universe and eventually awaken the Elder Gods to wipe away all mortal life, merely because he found current existence too boring his taste. Proving to be the most evil and dangerous of all the Mahjarrat, Sliske was the worst nightmare to ever come from the warped mind of the dying Mah.
- Amascut, Overarching Villain of the Desert Saga, became one of Gielinor's greatest evils when she became The Devourer. Once merely the pet cat of the Menaphite gods Tumeken and Elidinis, Amascut was the goddess of rebirth and worked alongside her brother Icthlarin to shepherd the dead to the afterlife. This all changed when her brother conscripted the Mahjarrat to fight the invading Zarosian Empire, and Amascut allegedly grew disgusted with their use of ritual sacrifice to retain longevity. Becoming The Devourer, Amascut blamed her family and swore to cause nothing but obliteration to everything physical and spiritual. She created monsters to devour souls in the underworld, erasing them from existence, merely to spite her brother. When her parents were banished, she began her bid for dominance by getting rid of the lesser desert gods. While how she managed to get most banished is unknown, the fate she delivered upon Apmeken, goddess of friendship, was by far the cruelest. She ripped away Apmeken's senses, turned them into demons, and had them slaughter Apmeken's sentient monkey followers. Her plans in modern times involved spreading war and conflict among the mortal populations of the desert. She tried to incite war between Al-Kharid and Menaphos by ransoming the kidnapped prince in exchange for the Kharid-ib diamond, managing to steal the diamond and its power in the process. She also created plagues that devastated Sophanem and tricked the followers of Scabaras into attacking the city to try to incite wars throughout the region. Her ultimate goal is to cause as much death and destruction as possible to give her more souls to devour and put the fear of death into the people of Gielinor.
- Bandos, the Big High War God, is a true believer in Might Makes Right and War is Glorious. As a mortal, Bandos happily murders the sleeping god, Jododu Otoku, despite knowing its death would lead to the extinction of all life on his homeworld. Now a god, he traveled to the world of Yu'biusk, homeworld of goblins, orks, and ogres, and transformed its inhabitants from peaceful hunter-gatherers to a brutish horde to serve as his soldiers, worshipers, and playthings. Marching his new army to the world of Gielinor, he ecstatically led them to battle during the cataclysmic God Wars. Constantly betraying his allies and spreading wanton slaughter, Bandos fought simply for the thrill of war. Eventually banished from Gielinor by Guthix at the end of the Third Age, Bandos took his frustration out on his remaining followers on Yu'biusk. He manipulated the remaining tribes into waging a war of total annihilation that turned Yu'biusk into a lifeless wasteland, just like Bandos's homeworld. In an attempt to return to Gielinor, he made Zanik, a member of the tribe of goblins that rebelled against him, into his Chosen Commander to lead his followers to wage total war on the rest of the Gielinor. Despite failing yet again, he returns following the death of Guthix with the intentions of killing the others gods and claiming the Stone of Jas to use its power to wage endless war across the universe. Hated and feared by mortals and gods alike, Bandos perfectly represents everything that can go wrong when a mortal ascends to godhood.