Complete Monster/Digimon


 * Professor Akihiro Kurata in Digimon Savers is the most despicable human villain to ever appear in the Digimon franchise. While Ken from Digimon Adventure 02 didn't think that he was doing anything wrong (and may or may not have been under More Than Mind Control), Oikawa was under Mind Control in a significant way, and Yamaki from Digimon Tamers was a Well-Intentioned Extremist who ultimately had a Heel Face Turn, Kurata's only goal is to Take Over the World and sadistically destroy all Digimon because of a petty grudge. Creating the Gizumon, mechanical monstrosities that make other Digimon Deader Than Dead by stopping them from reincarnating like usual, and experimenting in creating half-Digimon hybrids were only the start. Creating a weapon of mass destruction to kill thousands of Digimon in one shot, forcing the Teen Genius on the heroes' side to a Face Heel Turn by threatening to kill his Ill Girl little sister, trying to replicate his experiments on said Ill Girl, and finally awakening a mighty Demon Lord and merging with it to destroy all of his enemies so that he could then wipe out all Digimon and have total control of both the Digital World and the human world...well, that should give you an idea of how loathsome this guy is. And his motives? Petty greed, cowardice, prejudice, and an Inferiority Superiority Complex.
 * Let's not forget laughing hysterically as Ikuto/Keenan sobs over the loss of his surrogate father, whom his Gizumon have just permanently deleted. He is not just the most despicable human villain to ever appear in the Digimon franchise. He is the most despicable VILLAIN to ever appear in the franchise. Period. He even beat out Myotismon, the previous holder of the most complete monster in the series - not an easy feat.
 * A very good showing of just how horrid this guy is would be the reaction the heroes have to him in the last phase of the final battle. Basically, Kurata is the digimon equivalent of Doctor Weil.
 * Much less notorious than Kurata, but still an example nonetheless, is the evil MetalPhantomon from episode 15, who sadistically made Thomas suffer through the memory of his mother's death in order to suck out his lifeforce. This Is Unforgivable!, indeed.
 * Speaking of Myotismon. (Spoilers for the most Wham! Episode filled arcs of the first series ahead.) This guy was the most psychopathic villain of the series until Kurata came calling. First, he took in Gatomon under his wings in order to abuse and assault her to the point she became his loyal killing machine. He tortured his Ineffectual Sympathetic Villain minion Demi Devimon for petty reasons, entered the human world and destroyed much of Tokyo, killing several of his hench-mon along the way for the slightest failure (he very seldom leaves a minion alive, in fact), kidnapped almost every family in Odaiba and forced Gatomon to identify the children of said families as her partner in his search for the Eighth Child or he would kill them all, and killed poor Wizardmon (okay, Wizardmon had turned on him, but killing a Woobie will earn you major Jerkass points.) Any minions he hadn't already killed were cannibalized to fuel his Super Mode, and he was stopped just in time to prevent the entire population of Odaiba from becoming dessert.
 * Then he comes back and proves to be the mastermind of everything in the second season. He'd played on Oikawa's sadness and despair to use him as a pawn, his corrupting influence destroying Oikawa's body from within. Using kids to incubate his new power source wasn't nice, either, but the real reason Myo is seen as nigh-Kurata-level evil is what he did once he didn't need Arukenimon anymore: he subjected her to a painful and horrible death, while reading her mind and doing everything she feared he'd do to her in that order. The poor Dark Action Girl hadn't failed him; this was purely for the hell of it, and not only that, he infamously claimed to have been kinder with her because she was a woman. And when her Dogged Nice Guy Mummymon tried to avenge her, Myo gleefully incinerated him. Other Digimon Adventure villains can be Bad Bosses and tend to be Card Carrying Villains, but Myotismon's sadism is unparalleled - or was. (Yes, Kurata is worse.)
 * Piedmon is a psychotic Monster Clown who doesn't give a damn about life at all. He ruthlessly kills a large amount of the team's allies in brutal ways, and when the Digidestined finally face him down, he savagely beats them down before turning them into living keychains for him to toy with. The sequence where he hunts down the kids and their digimon one by one before transforming them, all while laughing with sadistic glee and mocking the two youngest team members (who he saves for last) is surprisingly frightening.
 * Seems the writers are aware of how big of monsters these two are: Piedmon and Myotismon are the only two Digimon Adventure villains who ultimately suffer a Fate Worse Than Death as well. Where Myotismon is ultimately killed Deader Than Dead (having his soul destroyed), Piedmon is sucked into MagnaAngemon's Gate of Destiny, a portal to a dimension from which he can never escape, and Digimon are pretty much immortal baring being killed outright.
 * While not on par with Myotismon or Piedmon in terms of sheer evil, Machinedramon also counts. Most Killer Robots are unfeeling killing machines. Machinedramon's Creepy Monotone would imply this applies to him too. But it's the things he actually says that pushes him into this. Practically everything he says shows he's a cold, calculating sadist who loves killing people. The most chilling line he has in the entire show is telling Kari, a little girl and one of the youngest Digidestined, that he is going to kill her in the most painful way he possibly can. And the combination of his sadistic lines and his Creepy Monotone make almost everything he says Nightmare Fuel. While he's not the worst Complete Monster in Digimon, he certainly makes the list.
 * Tactimon of Digimon Xros Wars bears special mention in that he was the one leader of Lord Bagra's armies with no positive or redeeming features about him. Not only is he responsible for rounding up several good Digimon into labor camps, including Cutemon's parents, but he was prepared to torture Mikey, a child, to death, as opposed to the quick, painless execution he could have ordered (not that that's any better; it just shows how sadistic Tactimon is). As if that wasn't bad enough, he's a full follower of the We Have Reserves mantra and has no compunctions about sacrificing his own subordinates for the sake of maintaining his supposedly perfect battle record, a practice that disgusted Dorulumon enough to defect from his side. Once he got out into the real world, he proceeded to lay waste to the entire area in hopes of getting his enemies killed and taking away what they value. Shortly afterwards, he attempts to murder Mikey, Angie, and Jeremy with his bare hands. When it comes time for him to do battle with his enemies, all he can feel is pure excitement over the thrill of combat and bloodshed.
 * Another example from the same series is Neo Myotismon, an Expy of Adventure's Myotismon and the second of Lord Bagramon's Death Generals. The ruler of the Vampire Land, he was characterized by only one thing: an undying thirst for power. He possesses familiar spirits known as Evilvils that seek out the life energy of Digimon and give it to him. Not only does he fuse both his minions and his enemies into himself, but he absorbs a great number of innocent Lopmon living in his domain in order to gain immortality from their hidden power. During his battle with the Fusion Fighters, he attempts to absorb Christopher's partner, Metal Greymon, into himself as well, forcing Metal Greymon into an And I Must Scream Body Horror situation
 * The other particularly heinous Death General is Gravimon, ruler of the Canyon Land. He uses his own core as a way to take Christopher hostage, and then reveals himself as a sadist who uses his cables to torture Christopher and probe his mind. He revels in the following Mind Rape, mercilessly playing off of Christopher's psyche until Christopher becomes broken enough to join him and obey his wishes. This set in motion the events that resulted in, among other things, the tragic death of Deckerdramon.
 * A minor example, but IceDevimon of Digimon Tamers certainly counts. Not content to merely load their data, he keeps the frozen remains of the Digimon he killed as a kind of trophy gallery. Notably, Ruki, who to this point had been rather ruthless regarding Digimon, is horrified.
 * If anything, IceDevimon in Digimon Frontier is just as bad, if not worse. Here he's an Ax Crazy killer whom even the current Big Bad didn't want anywhere near him!
 * Digimon Tamers: The D-Reaper from the Digital World was really just performing its' function but in a destructive way. The split D-Reaper that emerges in the real world, however, which includes J-Reaper and all the agents that follow it, is cold, calculating and intelligent, using Jeri's feelings to come to the conclusion that all humanity is worthless and must be purged. And it attempts to do so in insane and sadistic ways. It cares nothing for all life, not even it's own artificial existance, making it truly heartless.
 * Digimon Frontier also had Lucemon, a real nutjob with a Messiah complex, and the series' ultimate Big Bad. In his own warped, self righteous mind, Lucemon thinks that the Digital World has gone rotten and wants to tear it apart bit by bit, bringing about the loss of much data and the deaths of countless Digimon, all so he can rebuild it in his image: a utopia where every Digimon that lives is stripped of their free will and free thought, with Lucemon as their shepherd. In reality, what he intends to create is a Hell in Digi-world, where all Digimon are slaves and the only one who will be happy is him. To do this, he corrupted Cherubimon and made him the villain for most of the series, then used his two Royal Knight followers to erase data from the Digital World, and then once he was free, he disposed of said followers just to power him up. And he gets even worse when the digi-egg containing his darker side turns into Satan Mode, a being filled with nothing but darkness and malice. In this form, he attempts to claim the human world as well! Not to mention all the various tortures he inflicts on the good guys For the Evulz. Lucemon was, in the end, completely insane and never thoughtful of the lives of others: only himself, his pride, and his hatred towards a Digital World's existence not up to his standards.
 * An underrated but important example is Millenniummon of the Digimon Wonder Swan Series. He is responsible for the cataclysmic events of the Digimon universe, mainly the Adventure/Zero Two verse, such as releasing Apocalymon.
 * Also, when Milleniummon was destroyed, his data turned into Dark Spores and one buried itself into Ken's neck, exerting its influence on him. Since then, it grew within Ken and was later harvested and implanted into other children by Yukio Oikawa, meaning that Milleniummon is so evil that his data can corrupt anyone and turn them into insane and hateful beings, and Milleniummon is indirectly responsible for some of events in Digimon Adventure 02. Also, on the subject of releasing Apocalymon: in Digimon Wonder Swan Series, it is stated that Apocalymon's existence brought Devimon, Myotismon, and Dark Masters into existence. This means that, by releasing Apocalymon, Millenniumon is responsible for everything that goes down in Digimon Adventure and Digimon Adventure 02 and is responsible for the creation for some of the Complete Monsters in this page. Oh, and he was made from the data of Machinedramon. From Bad to Worse really applied here.