Snively: I don't see a heart, sir...
- Shadow the Hedgehog: Black Doom is the leader of the Black Arms and a completely humorless Evilutionary Biologist. Having visited the Earth for thousands of years, he made contact with Gerald Robotnik 50 years prior to the series, agreeing to a deal where a creation using Black Doom's cells, the future Shadow the Hedgehog, would deliver the Chaos Emeralds so that the Black Arms can use Chaos Control to arrive on Earth and bring prosperity to humanity. Gerald realized once Doom left that he was lied to, as Black Doom intended to enslave the human race and use them as a food source. During the events of the game, he preaches about the evils of humanity and how they don't deserve to be free, claiming they would be better served as a food source for the Black Arms, all while showing he has no regrets killing his own men or throwing away his "son" when everything is finished. During the game, he sends his army to kill millions, manipulated Shadow by forcing him to relive Maria's death, destroys an entire city—and most of his army—with the Eclipse Cannon, and spreads a gas that paralyzes Sonic and friends to make it easier for his offspring to eat them. Hypocritical, ruthless and uncaring to even his own, Black Doom is among the worst the franchise has to offer.
- Sonic the Hedgehog (2006): Mephiles the Dark is the malignant conscience of Solaris taken physical form and the one responsible for arranging most of the events of the game. Accidentally created during the Solaris Project alongside Iblis, the raw physical strength of Solaris, Mephiles was sealed within a scepter that landed in the hands of Dr. Eggman. Upon breaking out, Mephiles orchestrated a gambit which involved inflicting pain and suffering on Princess Elise, causing her to cry, release the Flames of Disaster, and in doing so would reunite him with Iblis to become Solaris, allowing him to destroy everything in existence. To do this, Mephiles manipulates Silver into attempting to kill Sonic, and later cold-bloodedly kills Sonic himself—temporarily—to goad Elise into crying over him. Mephiles manipulates everyone he can for the purpose of his ultimate goal and takes a sadistic glee in watching people suffer; unlike the mindless Iblis, Mephiles is fully aware of the scale of his atrocities and does them for no other reason than to see the world decay around him. A being that craved destruction alone, Mephiles's actions heavily damaged the space-time continuum and brought a darkness to the franchise seldom seen prior.
- Sonic and the Secret Rings: Erazor Djinn is a malevolent genie with aspirations of godhood and world domination. Having been forced to grant the wishes of 1,000 people as punishment for his crimes prior to the game, Erazor harbored a hatred for the creator of the Arabian Nights and sought to escape that storybook world. To that end, Erazor began to destroy and absorb the pages of the book to grow in power. When Shahra brings Sonic into the storybook to stop him, Erazor uses his Flame of Judgment curse to force Sonic into finding the Seven World Rings for him before the flame kills Sonic. He also commits other attrocites such as attempting to assassinate King Shahryar, summoning the Ifrit demon to burn the remaining pages of the book, and condemning King Solomon to life as an undead skeleton. When Sonic confronts Erazor at his palace, Erazor reveals his intention was to sacrifice Sonic to gain control of the Seven World Rings and reshape the world in his image. His attempt to kill Sonic is thwarted when Shahra takes the hit for Sonic. Erazor is unmoved by her sacrifice, calling her weak. Self-absorbed, and with the cruelty to match his ego, Erazor's transformation into Alf-Wayla-Wa-Layla only reflected the evil within his heart.
- Sonic Forces: Infinite is the high commander in the Eggman Empire and the primary reason behind the flawless conquest of Earth. Because of his position and power, Infinite took full part in the iron-fisted domination of 99.9% of the world, gleefully eliminating opposition, heroic or civilian, directly or by proxy through his illusions of Shadow, Chaos, Zavok, and Metal Sonic. He makes his introduction beating Sonic into unconsciousness for him to be imprisoned for six months. In the interlude, Infinite murders the Avatar's helpless friends, only sparing the Avatar so Infinite could relish their fear. He's put Omega out of commission from an early point to the finale; tried to kill Silver thanks to his love for ending heroes and instilling despair; and repeatedly tried to kill Sonic after his escape, only to not go through with it when Sonic is deemed not worth the effort. When the Resistance tried a full-scale assault on Metropolis, Infinite uses the Phantom Ruby to reduce them to even greater shambles. Later, he and Eggman try to trap Sonic in "null space", a void of eternal nothingness, to live out the rest of his days. At the climax, Infinite conjures a virtual sun to drop and burn everyone to death. A raving lunatic of a sadist, Infinite envisioned omnicidal designs even as a lowly thief and stands out for the reasons behind his sadism and hatred for weakness.
- Archie Comics series:
- The original Dr. Ivo Robotnik, during the Great War, intended to test weapons he'd developed for the government on his own people and fled to the Mobians' side when he was to be punished for his actions. While acting as warlord for King Acorn, he secretly captured a peaceful village of Mobian monkeys and utilized them in an early attempt to create mechanical slaves by surgically implanting cybernetics, and of that entire village only one survived the process. Afterwards, he sabotaged the Roboticizer developed by Charles Hedgehog just as it was to be used on his wounded brother Jules, making him think he'd turned his own brother into a mindless drone. When Jules's wife discovered the truth, Robotnik had Jules toss her into the Roboticizer and transformed into a robian as well, orphaning Sonic and crushing Charles's spirit to the point of retiring from being a science minister to running a chili dog stand. He then did similarly to Tails's father Amadeus on the day of his birth, making it seem as though Amadeus couldn't care less for his newborn son and subsequently shattering his wife's heart, throughout which Robotnik maintained a straight face. Afterwards followed his betrayal of King Acorn and the takeover of Mobius, during which countless families were broken and millions enslaved, and over the course of a decade, he'd wreak havoc upon planet Mobius, destroying the ecology and pushing more than a few Mobian breeds to the brink of extinction. Just prior to his death, he displayed a deeply disturbing relish at the thought of murdering one of his own kind, and was positively gleeful when he got the chance to use his latest and greatest weapon on a fellow overlander.
- General Kage Von Stryker is the leader of the Eggman-backed Dingo Regime. After ousting his father Helmut from power, Kage led his people in conquering Angel Island, imprisoning the Echidnas in what were clearly concentration camps, which led to countless deaths. He personally tortured Knuckles's father for the location of the Master Emerald, tried to wipe out the last echidna village on two occasions, and during the second attack boasted that he had crushed more Echidnas under his boot than he could remember. While like Helmut, Kage also hated the echidnas, unlike his father, Kage just wanted to kill them all.
- Dr. Finitevus was once a fellow scientist of a race of prosperous echidnas, until a freak accident changed his looks and intelligence. Despite his newfound genius, he was declared mentally unstable and was to be put down. He escaped and later sold out his home to Dr. Robotnik, resulting in everyone who had once lived there dying later. In addition, Finitevus manipulated four whole sides in a war—Dingoes, Echidnas, and two Dark Legion factions—into providing the fuel for the fire of his master plan, which is him deciding the world is hopelessly corrupt and wanting to purify it...in fire. He, to this end, manipulated Dimitri, a head in a jar, into providing secrets and information, and then manipulated Knux into becoming Knuxerjak and starting a battle with his former friends after the whole corruption from power thing. Finitevus's expression at the scene where Knux becomes Enerjak shows he is not only mad, but completely delighted, even as his betrayed allies watch on and denounce him.
- Hunter is a sociopathic Overlander known as a poacher of the Mobian kind. Hunter first debuts forcing Knuckles and his partner Monk into a hunt for their lives by threatening to murder Julie-Su, forcing the two to fight for their lives which ultimately leads to Monk's death. Though seemingly killed afterwards, Hunter is saved by Dr. Eggman and allows Hunter further work in his service, giving Hunter the chance to gleefully participate in Eggman's genocidal hunts and capture scores of innocent Mobians to have the life tortuously drained out of them in Eggman's Egg Grape Chambers, leading to the deaths of dozens. Proudly boasting of the various heads he keeps on his own wall of previous victims, Hunter's supposed sense of honor in his first appearance falls to reveal a sadistic mass murderer who hunts purely for the thrill of it.
- Worlds Unite crossover with Mega Man: Sigma was previously a hero and the leader of the Maverick Hunters. However, after fighting for a while he would start to see to Reploids as superior to humans and start a rebellion. Sigma and his forces would stage an attack on Arcadia City, bombing the city and having his forces kill off various Maverick Hunters who refused to join Sigma. Sigma returns as a computer virus and travels to the Sonic universe, where he forces Dr. Eggman, Dr. Wily, and the Deadly Six to help him in his plans, mostly with the Unity Engines with which Sigma intends to harness the power of entire worlds and conquer the multiverse. Sigma continues abusing the Genesis Portals—threatening to tear apart reality—all in his plan to become a god.
- Sonic the Comic:
- Emperor Metallix is the supreme leader of the Brotherhood of Metallix and one of the comic's most significant early villains. Going rogue from his intended purpose as one of Robotnik's drones, Emperor Metallix begins a crusade to wipe out all life from Mobius and replace it all with machinery. To this end, Metallix forcibly duplicates the Omni-viewer, callously ordering his double agent Nack the Weasel killed when he sells out the Chaotix before trying to terminate the Chaotix themselves. Metallix later drives a crusade to roboticize the Miracle Planet—enlisting Grimer's unwilling help and later threatening to kill Grimer before Sonic's eyes—and, succeeding at that, alters history so that Robotnik never comes into being and Emperor Metallix leads a successful assault on Mobius that leads to the death of most of the planet's organic life and the few survivors relegated underground. Emperor Metallix has no compunction brutally killing whatever stands in the way to it and its own victory, and even Dr. Robotnik rightfully fears and dreads what Emperor Metallix is capable of.
- Dr. Zachary, Knuckles's Arch-Enemy, is introduced as a seemingly harmless old man and one of the last of the echidnas. Zachary tricked Knuckles into leading him into the Emerald Chamber, whereupon he shattered the Master Emerald and used the Chaos Emeralds to empower a reprogrammed machine of his. Zachary gleefully allowed the inhabited floating island to fall onto Mobius as a "monument to his genius", intending to butcher the population of the planet Mobius for his own amusement before seeking revenge on Knuckles's people. In his second appearance, rebuilt as a cyborg, Zachary leads Robotnik to the location of the floating island's villagers so Robotnik could use them as components in a biological computer, which would consequentially kill them, a process which Zachary happily watched over. Possessed of a vindictive streak matched by few, Zachary manages to outshine most of the comic's other antagonists despite his relatively minor running as a villain.
- Chaos, the primary villain of the final arc, undergoes significant Adaptational Villainy from his game counterpart. Once a Drakon Prosecutor who fought for the glory of his cruel empire, Chaos was forcibly mutated into a beast made of Chaos Energy when he was exposed to the Chaos Emeralds. Sealed for a time, Chaos immediately goes on a destructive rampage once released by the careless exploit of Grimer, savagely killing Johnny Lightfoot during his confrontation with the Freedom Fighters. Once Chaos comes into contact with the Chaos Emeralds again, Chaos attempts to drain them—uncaring this will cause the populated island they support to collapse into the ocean—and later successfully manages to achieve his Perfect Chaos form upon absorbing them in Robotnik's fortress, announcing his intent to reshape the entire planet and purge everything not part of his destructive image. Online expands further on his villainy, where he's revealed to have constantly tortured the teenage Tikal for eight millennia while sealed away with her.
- Sonic the Comic Online!:
- In this Fan Webcomic that has received Approval of God, Dr. Zachary once again proves himself among the comic's nastiest. Zachary begins his new streak of evil by attempting to enslave Super Sonic to utilize his powers to wreak havoc across Mobius. Quickly cheated of that, Zachary builds up an alliance of like-minded psychopaths he calls The Syndicate and quickly builds a new plot to destroy Mobius utilizing the Chaos Emeralds. Snatching some of Sonic's DNA by capturing his young companion Tails and nearly drowning him, Zachary awakens the dormant Shadow the Hedgehog and uses his powers to draw the Chaos Emeralds out of the Special Zone, consequentially creating a massive chain reaction of Chaos Energy that obliterates the Special Zone and the billions of lives within. Brushing off the death of the Special Zone as a mere side effect of his plans, Zachary attempts to use a device he calls the Chaos Siphon to agitate the Chaos Energy on Mobius to the point where it causes an explosion potent enough to destroy the planet. Eventually foiled and captured by Knuckles, Zachary contents himself with sadistically mocking Knuckles about his failure to protect the Special Zone, and upon breaking out, forces Knuckles into a Sadistic Choice to either allow his friend Tikal to die or let the Floating Island collapse. A total sociopath as always who is utterly remorseless over the billions of lives lost to his machinations, Zachary proves he's no less of a monster here than he was in the original comic.
- Vichama note starts as an enigmatic flunky of Zachary enlisted in The Syndicate before revealing himself as something far worse. Vichama is in actuality the sadistic God of Death, an immortal entity who gained access to the physical plane through a deal with Pochacamac, using his new presence on Mobius to indiscriminately slaughter millions of echidnas. Trapping the souls of all of his murdered victims within his dark temple before he was banished, Vichama is brought back by Zachary and at first eagerly helps the doctor in his plot to destroy Mobius, helping to obliterate the Special Zone by proxy. Once Zachary's plot is foiled, Vichama leaves the doctor to die before rising his temple again and causing mass death through Mobius, assuming his true form as the God of Death. Casually incinerating Knuckles when he's confronted on his plot, Vichama announces his intent to bring the "gift of death" to everything that lives within the universe through all the enslaved souls in his thrall. Cloaking his murderous nature with a posh demeanor, Vichama is motivated by nothing less than a desire to spread mass death for its own sake and proves to be an utter bastard of a god who more than lives up to his title as the God of Death.
- Dr. Julian Robotnik is the absolute ruler of Mobius in the present day, having acquired the throne by betraying every person he used to be loyal to and using the monstrous Roboticizer to transform the planet into a hellish, mechanized dystopia. A tyrant whose only love is reserved for the pollution choking his entire empire, Robotnik subjects countless Mobians to Unwilling Roboticisation, a process they object to and fight against even after it happens. One of Robotnik's first victims of this was the Roboticizer's inventor, Sonic's own Uncle Chuck. Robotnik has mercilessly wiped out almost all resistance to his empire and tries time and time again to torture and kill Sonic and his Freedom Fighters, employing his "Doomsday Project" in the finale to kill off all life not already roboticized. Robotnik is also happy to execute his own worker-bots at his own whim and ultimately tries to leave all of his minions, including his long-abused nephew Snively, to die.