Complete Monster/Ben 10

File:VilgaxAttack.jpg  *Ben 10* and the other Cartoon Network series' set in its universe feature more than a few of these:

## *Ben 10*

### Franchise-Wide

* Vilgax is the overarching Villain of the franchise, and Ben's most personal enemy by far. He's a psychopathic galactic warlord who, after being banished from his homeworld due to his evil, went on to assault and conquer numerous planets across the cosmos, outright annihilating the entire planet of Petropia and its billions of inhabitants to make an example of those who resist him. After discovering the existence of the Omnitrix, Vilgax becomes obsessed with possessing the gadget to modify it for his own gain, and spends much of the first series sending wave after wave of his forces to Earth solely to kill Ben Tennyson, a 10-year-old boy, and steal the watch from him, later trying to viciously saw the boy's arm off and blow up the entire Earth for the trouble it has caused him. In *Ultimate Alien*, Vilgax becomes the herald for Diagon before betraying and killing his master and stealing his power, hoping to use it to mind control all life in the universe. In the final series, *Omniverse*, Vilgax, though at first seeming to have decayed in his evil, pulls out perhaps the most wicked scheme in the entire franchise, using a Chronosapien Time Bomb to wipe out all dimensions and timelines, his own included, to leave only a single, more submissive universe for him to conquer and rule. Vilgax was a madman who would kill first billions, then insurmountable trillions, just to satisfy his raging desire to be the most powerful being in the universe, and stands out as the most iconic villain in Ben 10 for this very reason.
* Ghostfreak is introduced as simply one of Ben's ten original forms in the Omnitrix called "Ghostfreak", and one that disturbs him so much he is reluctant to use it, particular after he almost killed Zombozo in that form. Then it turns out Z'Skayr's memory and personality is still contained inside the Omnitrix along with his DNA, allowing him to resurrect from Ben's transformation, and he just happens to be a maniacal alien tyrant who wants to take Ben's body and use it to his own ends. He possesses Ben's cousin Gwen and threatened to make her commit suicide in order to get to Ben, and after Ben submits to him, he still makes Gwen jump off the building! He later returned and tried to permanently damage and mutate the Earth in order to rule over it. The mutation of Earth is shown on-screen and it **really** isn't pretty. Z'Skayr remains sadistic, merciless and power-hungry in the other series, too: in *Alien Force*, he successfully mutates all life on Vilgax's planet into ghost mutants and plans to do the same to the rest of the universe, and in *Omniverse*, he unleashes a horrific vampire alien upon his own home planet in order to reconquer it for himself.
* Eon is an evil alternate Ben Tennyson who traverses the space-time continuum enslaving the Bens of different timelines to becomes his brainwashed servants. After getting banished from the *Race Against Time* timeline, Eon tricks Ben-Prime and Ben 10,000 into using the Hands of Armageddon to free him and intends to eliminate both Bens so that Eon can create a new timeline where he is the sole Ben Tennyson. Trapped in the main timeline, Eon attempts to acquire Professor Paradox's Chrononavigator so he can freely travel, luring Paradox over by performing a temporal brain swap between the 11 and 16 year old Bens. Ignoring Paradox's warnings, Eon's rampant abuse of the Chrononavigator ruptures the timestream, with Eon declaring that if he couldn't rule reality he would destroy it instead. Eon returns allied with Vilgax, where he recruits evil Bens from throughout the cosmos to attack the No Watch timeline and was ecstatic when he believed Vilgax would nuke said timeline. Eon also assists Maltraunt in his plan to rewrite reality, by gathering Time Beasts. Having endangered the entire cosmos multiple times for his own selfish goals, Eon earns a place as one of the most vile villains to ever appear.

### Original Series

* While the original series' incarnation of Kevin 11 was already a sociopath of a mutant who'd destroy two trains full of innocent civilians for cash, killed a police officer with no regrets, killed an alien just to take a ship and crew he'd use to spread terror and death over the galaxy, turned down at least **three** chances at redemption (with Ben even calling him out on how his Freudian Excuse can no longer be a valid way of excusing away his crimes) and, when he and Ben were forced to work together, ended up trying to kill Ben through **impaling him** and whose attacks on Ben and his family were more vicious than most foes save for the other examples on this page, redemption wasn't entirely impossible for the kid. However, the Alternate Timeline episode *Ken 10* shows us what he'd become if he'd stayed on the road to evil: enter Kevin 11,000. Unlike his younger self, who merely straddled the line of the trope, Kevin 11,000 is a fully-fledged case as he now seems much more in control of his emotions as he is in control of his powers and is fully aware of what he's doing - he just continues to do terrible things simply because he gets enjoyment out of it. To spite his old nemesis, he tries to murder Ben's **10-year-old son** and would've likely killed his **own** son just to do it - **that's** how little he cares for anyone who's not himself.

### *Alien Force*

* In Season 3's "Vendetta", Ragnarok is a criminal who makes a living by using his ship to drain stars of their energy for profit, killing all life in the star system that depended upon said star. He attempted to do this to the Sun, before being stopped and imprisoned in the Null Void, allegedly killing a plumber Devin Levin. Escaping imprisonment years later, he once again resumes his attempts to drain the sun by finding the key to his ship, where at one point he sadistically beat Kevin to near-death in his search for the key, and upon finally acquiring the key he resumes draining the sun.

=== *Ultimate Alien*===\*Aggregor is an Osmodian who kidnaps aliens from different planets to zap their powers and use them as his own. What cements him as a Complete Monster is when he kills a peaceful turtle alien **on-screen**, and then turns its powers against its brethren before kidnapping the main one. He then kills the plumber from Season 2 of *Alien Force* by stabbing him in the back when he found the prisoners. He manages to top himself, when learning of the Ultimatrix, he tries to force Ben into a form he wanted after a no-holds-barred shock down by **stabbing** him right in the Ultimatrix icon with his spear and **twisting** it. If not for the Heroic Sacrifice of the jellyfish alien, Ben would have **died**, since both Kevin and Gwen were down. His vilest crimes were when he nearly destroyed an inhabited world by stealing a component from the device that kept the planet from breaking apart, and when he attempted to kill and absorb a baby alien capable of Reality Warping to complete his ascension into godhood

* *Ultimate Alien* also gave us Diagon, who's an Expy of the original series' Vilgax in characterization, only with the Cthulhumanoid played up to the ultimate extent. He's also the one who offers a temporarily corrupted Charmcaster 600,000 living souls in exchange for a wish and, given that he lives through dark mana, possibly even had a hand in Charmcaster and her uncle Hex being corrupted to start with!

### *Omniverse*

* Malware, the true Big Bad of Season 1 and Khyber's boss, is a psychotic Galvanic Mechamorph born with a malfunction forcing him to sustain himself by cannibalizing people of his own species in exchange of the ability to copy technology by consuming it. His onscreen actions include trying to crash a school bus just to distract Ben, Template:Spoiler. He especially stands out as this trope amongst *Ben 10* villains, because, despite being in the most goofy and light-hearted entry in the franchise, his viciousness and cruelty rivals the likes of Vilgax, Z'Skayr, and Aggregor.
* The final Big Bad of *Omniverse*, Maltruant, is a rogue Chronosapien bent on ruling all of time and existence who masterminded the original Time War in his first bid for universal control. He was defeated and his body separated across time by Professor Paradox. Seeking to restart the Time War, he hired Dr. Psychobos to help repair himself. After his Co-Dragons Subdora and Exo-Skull complete repairing his body, Maltruant turned on Dr. Psychobos, easily defeated Ben Prime and Ben 23, and left both for dead in Mad Ben's dimension with his minions to restart the Time War. Once he travels to the time period of Ben 10,000 to steal the Anihilaarg and the Dwarf Star so he can create a more deadly weapon, Maltruant traveled back to the very beginning of the universe and snuck aboard the Contemelia's ship, where he switched their Anihilaarg with his own in order to recreate the universe in his own image. Despite his Laughably Evil traits, Maltruant cemented himself as one of Ben's most monstrous enemies through his egomania and greed.

### 2016 Reboot

* The High Override is a warlord and the leader of the Fulmini empire, who has harvested countless planets for their energy. He sets his sights on Earth after discovering its existence through Ben using using Shock Rock, the Omnitrix's DNA sample of a Fulmini. At first, manipulating Ben as Shock Rock as a voice in his head before taking over his body during Ben's sleep, High Override makes Ben construct a beacon to allow a portal to opened for the Fulmini to invade. When resisted by Ben and Vilgax, High Override takes over Shock Rock's mind and forces him to attack his friends, while banishing Vilgax into the Null Void. One of the most dangerous threats in the show, the High Override set a serious tone scarcely seen from other villains.
* The Forever Knight is a mysterious armored mastermind whose goal is to go back in time and prevent alien signals from contacting Earth so that alien species and humanity never interact. Throughout Season 3, Forever Knight tests Team Tennyson and their adversaries to determine who and what he can exploit for carrying out his agenda, often by influencing crimes or creating disasters that put many in harm's way. Preying on the younger foes such as Billy Billions, Simon Sez and Charmcaster, he eventually found his ideal pawn in Kevin 11, who initially turns down the Knight's offer to serve him until the Knight threatened the life of Gwen Tennyson, for whom Kevin harbored affections. During Kevin's time taking on missions for him, Forever Knight frequently goads the boy and disparages him as a "cheap Tennyson knock-off" so that his resentment and spite may better motivate him, also openly stating he believes that without him, Kevin has no one, and that Kevin is his personal belonging. Forever Knight doesn't hesitate to attempt to kill Kevin for disobedience, beats the tar out of Ben in their first physical confronting, and during a later gladiatorial fight between Kevin and Ben, he raises the stakes with no concern for the kids' safety. Arrogant, callous and predatorial, the Forever Knight in this series is an Expy of Slade Wilson from *Teen Titans*, making him notably darker and crueler than the other villains on the show.