History Sandbox / MonsterSonicTheHedgehog

* ''ComicBook/{{Mega Man| Archie Comics}}'''s "Dawn of X" arc & ''[[ComicBook/SonicTheHedgehogMegaManWorldsUnite Worlds Unite]]'' {{crossover}}: [[Characters/MegaManXSigma Sigma]] was previously a [[FallenHero hero]] and the leader of the Maverick Hunters. However, after fighting for a while, Sigma would start to see [[FantasticRacism Reploids as superior to humans]] and start a rebellion. Sigma 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 [[PlanetaryCoreManipulation 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 [[GodhoodSeeker become a god]].

-->— '''[[Characters/SonicTheHedgehogInfinite Infinite]]''', ''VideoGame/SonicForces''

''Franchise/SonicTheHedgehog'', though [[VileVillainSaccharineShow usually a lighthearted franchise]], becomes [[KnightOfCerebus much darker]] when [[CompleteMonster these characters]] show up.

* ''VideoGame/ShadowTheHedgehog'': [[NotSoWellIntentionedExtremist Black Doom]] is the leader of the [[AliensAreBastards Black Arms]] and a completely humorless EvilutionaryBiologist. Having visited the Earth for thousands of years, he [[VideoGame/SonicAdventure2 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 [[ToServeMan food source]]. During the events of the game, he preaches about the [[KnightTemplar 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 [[YouHaveOutlivedYourUsefulness 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. [[{{Hypocrite}} Hypocritical]], ruthless and uncaring to even his own, Black Doom is among the worst the franchise has to offer.

* ''[[VideoGame/SonicForces Forces]]'': [[Characters/SonicTheHedgehogInfinite Infinite]] is [[TheHeavy 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 [[EstablishingCharacterMoment 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 [[CruelMercy 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 [[HeroKiller 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 "[[AndIMustScream null space]]", a void of eternal nothingness, to live out the rest of his days. At the climax, Infinite [[ColonyDrop conjures a virtual sun to drop and burn everyone to death]]. A [[AxCrazy 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.